--- _id: '18466' abstract: - lang: eng text: The transverse dynamic spin susceptibility is a correlation function that yields exact information about spin excitations in systems with a collinear magnetic ground state, including collective spin-wave modes. In an ab initio context, it may be calculated within many-body perturbation theory or time-dependent density-functional theory, but the quantitative accuracy is currently limited by the available functionals for exchange and correlation in dynamically evolving systems. To circumvent this limitation, the spin susceptibility is here alternatively formulated as the solution of an initial-value problem. In this way, the challenge of accurately describing exchange and correlation in many-electron systems is shifted to the stationary initial state, which is much better understood. The proposed scheme further requires the choice of an auxiliary basis set, which determines the speed of convergence but always allows systematic convergence in practical implementations. article_number: '3732892' article_type: original author: - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X citation: ama: Schindlmayr A. Exact formulation of the transverse dynamic spin susceptibility as an initial-value problem. Advances in Mathematical Physics. 2018;2018. doi:10.1155/2018/3732892 apa: Schindlmayr, A. (2018). Exact formulation of the transverse dynamic spin susceptibility as an initial-value problem. Advances in Mathematical Physics, 2018, Article 3732892. https://doi.org/10.1155/2018/3732892 bibtex: '@article{Schindlmayr_2018, title={Exact formulation of the transverse dynamic spin susceptibility as an initial-value problem}, volume={2018}, DOI={10.1155/2018/3732892}, number={3732892}, journal={Advances in Mathematical Physics}, publisher={Hindawi}, author={Schindlmayr, Arno}, year={2018} }' chicago: Schindlmayr, Arno. “Exact Formulation of the Transverse Dynamic Spin Susceptibility as an Initial-Value Problem.” Advances in Mathematical Physics 2018 (2018). https://doi.org/10.1155/2018/3732892. ieee: 'A. Schindlmayr, “Exact formulation of the transverse dynamic spin susceptibility as an initial-value problem,” Advances in Mathematical Physics, vol. 2018, Art. no. 3732892, 2018, doi: 10.1155/2018/3732892.' mla: Schindlmayr, Arno. “Exact Formulation of the Transverse Dynamic Spin Susceptibility as an Initial-Value Problem.” Advances in Mathematical Physics, vol. 2018, 3732892, Hindawi, 2018, doi:10.1155/2018/3732892. short: A. Schindlmayr, Advances in Mathematical Physics 2018 (2018). date_created: 2020-08-27T19:18:34Z date_updated: 2025-12-16T08:04:17Z ddc: - '530' department: - _id: '296' - _id: '35' - _id: '15' - _id: '170' - _id: '230' doi: 10.1155/2018/3732892 external_id: isi: - '000422773000001' file: - access_level: open_access content_type: application/pdf creator: schindlm date_created: 2020-08-28T09:18:25Z date_updated: 2020-08-30T14:31:38Z description: Creative Commons Attribution 4.0 International Public License (CC BY 4.0) file_id: '18537' file_name: 3732892.pdf file_size: 294410 relation: main_file title: Exact formulation of the transverse dynamic spin susceptibility as an initial-value problem file_date_updated: 2020-08-30T14:31:38Z has_accepted_license: '1' intvolume: ' 2018' isi: '1' language: - iso: eng oa: '1' publication: Advances in Mathematical Physics publication_identifier: eissn: - 1687-9139 issn: - 1687-9120 publication_status: published publisher: Hindawi quality_controlled: '1' status: public title: Exact formulation of the transverse dynamic spin susceptibility as an initial-value problem type: journal_article user_id: '16199' volume: 2018 year: '2018' ... --- _id: '10023' abstract: - lang: eng text: We perform a comprehensive theoretical study of the structural and electronic properties of potassium niobate (KNbO3) in the cubic, tetragonal, orthorhombic, monoclinic, and rhombohedral phase, based on density-functional theory. The influence of different parametrizations of the exchange-correlation functional on the investigated properties is analyzed in detail, and the results are compared to available experimental data. We argue that the PBEsol and AM05 generalized gradient approximations as well as the RTPSS meta-generalized gradient approximation yield consistently accurate structural data for both the external and internal degrees of freedom and are overall superior to the local-density approximation or other conventional generalized gradient approximations for the structural characterization of KNbO3. Band-structure calculations using a HSE-type hybrid functional further indicate significant near degeneracies of band-edge states in all phases which are expected to be relevant for the optical response of the material. article_number: '3981317' article_type: original author: - first_name: Falko full_name: Schmidt, Falko id: '35251' last_name: Schmidt orcid: 0000-0002-5071-5528 - first_name: Marc full_name: Landmann, Marc last_name: Landmann - first_name: Eva full_name: Rauls, Eva last_name: Rauls - first_name: Nicola full_name: Argiolas, Nicola last_name: Argiolas - first_name: Simone full_name: Sanna, Simone last_name: Sanna - first_name: Wolf Gero full_name: Schmidt, Wolf Gero id: '468' last_name: Schmidt orcid: 0000-0002-2717-5076 - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X citation: ama: Schmidt F, Landmann M, Rauls E, et al. Consistent atomic geometries and electronic structure of five phases of potassium niobate from density-functional theory. Advances in Materials Science and Engineering. 2017;2017. doi:10.1155/2017/3981317 apa: Schmidt, F., Landmann, M., Rauls, E., Argiolas, N., Sanna, S., Schmidt, W. G., & Schindlmayr, A. (2017). Consistent atomic geometries and electronic structure of five phases of potassium niobate from density-functional theory. Advances in Materials Science and Engineering, 2017, Article 3981317. https://doi.org/10.1155/2017/3981317 bibtex: '@article{Schmidt_Landmann_Rauls_Argiolas_Sanna_Schmidt_Schindlmayr_2017, title={Consistent atomic geometries and electronic structure of five phases of potassium niobate from density-functional theory}, volume={2017}, DOI={10.1155/2017/3981317}, number={3981317}, journal={Advances in Materials Science and Engineering}, publisher={Hindawi}, author={Schmidt, Falko and Landmann, Marc and Rauls, Eva and Argiolas, Nicola and Sanna, Simone and Schmidt, Wolf Gero and Schindlmayr, Arno}, year={2017} }' chicago: Schmidt, Falko, Marc Landmann, Eva Rauls, Nicola Argiolas, Simone Sanna, Wolf Gero Schmidt, and Arno Schindlmayr. “Consistent Atomic Geometries and Electronic Structure of Five Phases of Potassium Niobate from Density-Functional Theory.” Advances in Materials Science and Engineering 2017 (2017). https://doi.org/10.1155/2017/3981317. ieee: 'F. Schmidt et al., “Consistent atomic geometries and electronic structure of five phases of potassium niobate from density-functional theory,” Advances in Materials Science and Engineering, vol. 2017, Art. no. 3981317, 2017, doi: 10.1155/2017/3981317.' mla: Schmidt, Falko, et al. “Consistent Atomic Geometries and Electronic Structure of Five Phases of Potassium Niobate from Density-Functional Theory.” Advances in Materials Science and Engineering, vol. 2017, 3981317, Hindawi, 2017, doi:10.1155/2017/3981317. short: F. Schmidt, M. Landmann, E. Rauls, N. Argiolas, S. Sanna, W.G. Schmidt, A. Schindlmayr, Advances in Materials Science and Engineering 2017 (2017). date_created: 2019-05-29T07:48:32Z date_updated: 2025-12-05T09:58:11Z ddc: - '530' department: - _id: '295' - _id: '296' - _id: '230' - _id: '429' - _id: '15' - _id: '35' - _id: '27' doi: 10.1155/2017/3981317 external_id: isi: - '000394873300001' file: - access_level: open_access content_type: application/pdf creator: schindlm date_created: 2020-08-28T09:27:19Z date_updated: 2020-08-30T14:37:31Z description: Creative Commons Attribution 4.0 International Public License (CC BY 4.0) file_id: '18538' file_name: 3981317.pdf file_size: 985948 relation: main_file title: Consistent atomic geometries and electronic structure of five phases of potassium niobate from density-functional theory file_date_updated: 2020-08-30T14:37:31Z has_accepted_license: '1' intvolume: ' 2017' isi: '1' language: - iso: eng oa: '1' project: - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing - _id: '53' name: TRR 142 - _id: '55' name: TRR 142 - Project Area B - _id: '69' name: TRR 142 - Subproject B4 - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing publication: Advances in Materials Science and Engineering publication_identifier: eissn: - 1687-8442 issn: - 1687-8434 publication_status: published publisher: Hindawi quality_controlled: '1' status: public title: Consistent atomic geometries and electronic structure of five phases of potassium niobate from density-functional theory type: journal_article user_id: '16199' volume: 2017 year: '2017' ... --- _id: '10021' abstract: - lang: eng text: The optical properties of pristine and titanium-doped LiNbO3 are modeled from first principles. The dielectric functions are calculated within time-dependent density-functional theory, and a model long-range contribution is employed for the exchange-correlation kernel in order to account for the electron-hole binding. Our study focuses on the influence of substitutional titanium atoms on lithium sites. We show that an increasing titanium concentration enhances the values of the refractive indices and the reflectivity. article_number: '034401' article_type: original author: - first_name: Michael full_name: Friedrich, Michael last_name: Friedrich - first_name: Wolf Gero full_name: Schmidt, Wolf Gero id: '468' last_name: Schmidt orcid: 0000-0002-2717-5076 - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X - first_name: Simone full_name: Sanna, Simone last_name: Sanna citation: ama: Friedrich M, Schmidt WG, Schindlmayr A, Sanna S. Optical properties of titanium-doped lithium niobate from time-dependent density-functional theory. Physical Review Materials. 2017;1(3). doi:10.1103/PhysRevMaterials.1.034401 apa: Friedrich, M., Schmidt, W. G., Schindlmayr, A., & Sanna, S. (2017). Optical properties of titanium-doped lithium niobate from time-dependent density-functional theory. Physical Review Materials, 1(3), Article 034401. https://doi.org/10.1103/PhysRevMaterials.1.034401 bibtex: '@article{Friedrich_Schmidt_Schindlmayr_Sanna_2017, title={Optical properties of titanium-doped lithium niobate from time-dependent density-functional theory}, volume={1}, DOI={10.1103/PhysRevMaterials.1.034401}, number={3034401}, journal={Physical Review Materials}, publisher={American Physical Society}, author={Friedrich, Michael and Schmidt, Wolf Gero and Schindlmayr, Arno and Sanna, Simone}, year={2017} }' chicago: Friedrich, Michael, Wolf Gero Schmidt, Arno Schindlmayr, and Simone Sanna. “Optical Properties of Titanium-Doped Lithium Niobate from Time-Dependent Density-Functional Theory.” Physical Review Materials 1, no. 3 (2017). https://doi.org/10.1103/PhysRevMaterials.1.034401. ieee: 'M. Friedrich, W. G. Schmidt, A. Schindlmayr, and S. Sanna, “Optical properties of titanium-doped lithium niobate from time-dependent density-functional theory,” Physical Review Materials, vol. 1, no. 3, Art. no. 034401, 2017, doi: 10.1103/PhysRevMaterials.1.034401.' mla: Friedrich, Michael, et al. “Optical Properties of Titanium-Doped Lithium Niobate from Time-Dependent Density-Functional Theory.” Physical Review Materials, vol. 1, no. 3, 034401, American Physical Society, 2017, doi:10.1103/PhysRevMaterials.1.034401. short: M. Friedrich, W.G. Schmidt, A. Schindlmayr, S. Sanna, Physical Review Materials 1 (2017). date_created: 2019-05-29T07:42:33Z date_updated: 2025-12-05T10:07:07Z ddc: - '530' department: - _id: '295' - _id: '296' - _id: '230' - _id: '429' - _id: '35' - _id: '27' doi: 10.1103/PhysRevMaterials.1.034401 external_id: isi: - '000416562300001' file: - access_level: open_access content_type: application/pdf creator: schindlm date_created: 2020-08-27T19:39:54Z date_updated: 2020-08-30T14:36:11Z description: © 2017 American Physical Society file_id: '18467' file_name: PhysRevMaterials.1.034401.pdf file_size: 708075 relation: main_file title: Optical properties of titanium-doped lithium niobate from time-dependent density-functional theory file_date_updated: 2020-08-30T14:36:11Z has_accepted_license: '1' intvolume: ' 1' isi: '1' issue: '3' language: - iso: eng oa: '1' project: - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing - _id: '53' name: TRR 142 - _id: '55' name: TRR 142 - Project Area B - _id: '69' name: TRR 142 - Subproject B4 - _id: '68' name: TRR 142 - Subproject B3 publication: Physical Review Materials publication_identifier: issn: - 2475-9953 publication_status: published publisher: American Physical Society quality_controlled: '1' related_material: record: - id: '13410' relation: other status: public status: public title: Optical properties of titanium-doped lithium niobate from time-dependent density-functional theory type: journal_article user_id: '16199' volume: 1 year: '2017' ... --- _id: '13416' abstract: - lang: eng text: 'The optical properties of congruent lithium niobate are analyzed from first principles. The dielectric function of the material is calculated within time-dependent density-functional theory. The effects of isolated intrinsic defects and defect pairs, including the NbLi4+ antisite and the NbLi4+−NbNb4+ pair, commonly addressed as a bound polaron and bipolaron, respectively, are discussed in detail. In addition, we present further possible realizations of polaronic and bipolaronic systems. The absorption feature around 1.64 eV, ascribed to small bound polarons [O. F. Schirmer et al., J. Phys.: Condens. Matter 21, 123201 (2009)], is nicely reproduced within these models. Among the investigated defects, we find that the presence of bipolarons at bound interstitial-vacancy pairs NbV−VLi can best explain the experimentally observed broad absorption band at 2.5 eV. Our results provide a microscopic model for the observed optical spectra and suggest that, besides NbLi antisites and Nb and Li vacancies, Nb interstitials are also formed in congruent lithium-niobate samples.' article_number: '054406' article_type: original author: - first_name: Michael full_name: Friedrich, Michael last_name: Friedrich - first_name: Wolf Gero full_name: Schmidt, Wolf Gero id: '468' last_name: Schmidt orcid: 0000-0002-2717-5076 - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X - first_name: Simone full_name: Sanna, Simone last_name: Sanna citation: ama: Friedrich M, Schmidt WG, Schindlmayr A, Sanna S. Polaron optical absorption in congruent lithium niobate from time-dependent density-functional theory. Physical Review Materials. 2017;1(5). doi:10.1103/PhysRevMaterials.1.054406 apa: Friedrich, M., Schmidt, W. G., Schindlmayr, A., & Sanna, S. (2017). Polaron optical absorption in congruent lithium niobate from time-dependent density-functional theory. Physical Review Materials, 1(5), Article 054406. https://doi.org/10.1103/PhysRevMaterials.1.054406 bibtex: '@article{Friedrich_Schmidt_Schindlmayr_Sanna_2017, title={Polaron optical absorption in congruent lithium niobate from time-dependent density-functional theory}, volume={1}, DOI={10.1103/PhysRevMaterials.1.054406}, number={5054406}, journal={Physical Review Materials}, publisher={American Physical Society}, author={Friedrich, Michael and Schmidt, Wolf Gero and Schindlmayr, Arno and Sanna, Simone}, year={2017} }' chicago: Friedrich, Michael, Wolf Gero Schmidt, Arno Schindlmayr, and Simone Sanna. “Polaron Optical Absorption in Congruent Lithium Niobate from Time-Dependent Density-Functional Theory.” Physical Review Materials 1, no. 5 (2017). https://doi.org/10.1103/PhysRevMaterials.1.054406. ieee: 'M. Friedrich, W. G. Schmidt, A. Schindlmayr, and S. Sanna, “Polaron optical absorption in congruent lithium niobate from time-dependent density-functional theory,” Physical Review Materials, vol. 1, no. 5, Art. no. 054406, 2017, doi: 10.1103/PhysRevMaterials.1.054406.' mla: Friedrich, Michael, et al. “Polaron Optical Absorption in Congruent Lithium Niobate from Time-Dependent Density-Functional Theory.” Physical Review Materials, vol. 1, no. 5, 054406, American Physical Society, 2017, doi:10.1103/PhysRevMaterials.1.054406. short: M. Friedrich, W.G. Schmidt, A. Schindlmayr, S. Sanna, Physical Review Materials 1 (2017). date_created: 2019-09-20T11:54:25Z date_updated: 2025-12-05T10:14:23Z ddc: - '530' department: - _id: '296' - _id: '295' - _id: '230' - _id: '429' - _id: '35' - _id: '15' - _id: '27' doi: 10.1103/PhysRevMaterials.1.054406 external_id: isi: - '000416586100003' file: - access_level: open_access content_type: application/pdf creator: schindlm date_created: 2020-08-27T19:43:49Z date_updated: 2020-08-30T14:38:50Z description: © 2017 American Physical Society file_id: '18468' file_name: PhysRevMaterials.1.054406.pdf file_size: 1417182 relation: main_file title: Polaron optical absorption in congruent lithium niobate from time-dependent density-functional theory file_date_updated: 2020-08-30T14:38:50Z has_accepted_license: '1' intvolume: ' 1' isi: '1' issue: '5' language: - iso: eng oa: '1' project: - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing - _id: '53' name: TRR 142 - _id: '55' name: TRR 142 - Project Area B - _id: '68' name: TRR 142 - Subproject B3 - _id: '69' name: TRR 142 - Subproject B4 publication: Physical Review Materials publication_identifier: eissn: - 2475-9953 publication_status: published publisher: American Physical Society quality_controlled: '1' status: public title: Polaron optical absorption in congruent lithium niobate from time-dependent density-functional theory type: journal_article user_id: '16199' volume: 1 year: '2017' ... --- _id: '7481' abstract: - lang: eng text: The electronic band structures of hexagonal ZnO and cubic ZnS, ZnSe, and ZnTe compounds are determined within hybrid-density-functional theory and quasiparticle calculations. It is found that the band-edge energies calculated on the G0W0 (Zn chalcogenides) or GW (ZnO) level of theory agree well with experiment, while fully self-consistent QSGW calculations are required for the correct description of the Zn 3d bands. The quasiparticle band structures are used to calculate the linear response and second-harmonic-generation (SHG) spectra of the Zn–VI compounds. Excitonic effects in the optical absorption are accounted for within the Bethe–Salpeter approach. The calculated spectra are discussed in the context of previous experimental data and present SHG measurements for ZnO. article_number: '215702' article_type: original author: - first_name: Arthur full_name: Riefer, Arthur last_name: Riefer - first_name: Nils full_name: Weber, Nils last_name: Weber - first_name: Johannes full_name: Mund, Johannes last_name: Mund - first_name: Dmitri R. full_name: Yakovlev, Dmitri R. last_name: Yakovlev - first_name: Manfred full_name: Bayer, Manfred last_name: Bayer - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X - first_name: Cedrik full_name: Meier, Cedrik id: '20798' last_name: Meier orcid: https://orcid.org/0000-0002-3787-3572 - first_name: Wolf Gero full_name: Schmidt, Wolf Gero id: '468' last_name: Schmidt orcid: 0000-0002-2717-5076 citation: ama: 'Riefer A, Weber N, Mund J, et al. Zn–VI quasiparticle gaps and optical spectra from many-body calculations. Journal of Physics: Condensed Matter. 2017;29(21). doi:10.1088/1361-648x/aa6b2a' apa: 'Riefer, A., Weber, N., Mund, J., Yakovlev, D. R., Bayer, M., Schindlmayr, A., Meier, C., & Schmidt, W. G. (2017). Zn–VI quasiparticle gaps and optical spectra from many-body calculations. Journal of Physics: Condensed Matter, 29(21), Article 215702. https://doi.org/10.1088/1361-648x/aa6b2a' bibtex: '@article{Riefer_Weber_Mund_Yakovlev_Bayer_Schindlmayr_Meier_Schmidt_2017, title={Zn–VI quasiparticle gaps and optical spectra from many-body calculations}, volume={29}, DOI={10.1088/1361-648x/aa6b2a}, number={21215702}, journal={Journal of Physics: Condensed Matter}, publisher={IOP Publishing}, author={Riefer, Arthur and Weber, Nils and Mund, Johannes and Yakovlev, Dmitri R. and Bayer, Manfred and Schindlmayr, Arno and Meier, Cedrik and Schmidt, Wolf Gero}, year={2017} }' chicago: 'Riefer, Arthur, Nils Weber, Johannes Mund, Dmitri R. Yakovlev, Manfred Bayer, Arno Schindlmayr, Cedrik Meier, and Wolf Gero Schmidt. “Zn–VI Quasiparticle Gaps and Optical Spectra from Many-Body Calculations.” Journal of Physics: Condensed Matter 29, no. 21 (2017). https://doi.org/10.1088/1361-648x/aa6b2a.' ieee: 'A. Riefer et al., “Zn–VI quasiparticle gaps and optical spectra from many-body calculations,” Journal of Physics: Condensed Matter, vol. 29, no. 21, Art. no. 215702, 2017, doi: 10.1088/1361-648x/aa6b2a.' mla: 'Riefer, Arthur, et al. “Zn–VI Quasiparticle Gaps and Optical Spectra from Many-Body Calculations.” Journal of Physics: Condensed Matter, vol. 29, no. 21, 215702, IOP Publishing, 2017, doi:10.1088/1361-648x/aa6b2a.' short: 'A. Riefer, N. Weber, J. Mund, D.R. Yakovlev, M. Bayer, A. Schindlmayr, C. Meier, W.G. Schmidt, Journal of Physics: Condensed Matter 29 (2017).' date_created: 2019-02-04T13:46:58Z date_updated: 2025-12-16T11:07:33Z ddc: - '530' department: - _id: '287' - _id: '295' - _id: '296' - _id: '230' - _id: '429' - _id: '35' - _id: '15' - _id: '170' - _id: '429' - _id: '27' doi: 10.1088/1361-648x/aa6b2a external_id: isi: - '000400093100001' pmid: - '28374685' file: - access_level: closed content_type: application/pdf creator: schindlm date_created: 2020-08-28T14:01:15Z date_updated: 2020-08-30T14:34:08Z description: © 2017 IOP Publishing Ltd file_id: '18574' file_name: Riefer_2017_J._Phys. _Condens._Matter_29_215702.pdf file_size: 2551657 relation: main_file title: Zn–VI quasiparticle gaps and optical spectra from many-body calculations file_date_updated: 2020-08-30T14:34:08Z has_accepted_license: '1' intvolume: ' 29' isi: '1' issue: '21' language: - iso: eng pmid: '1' project: - _id: '53' name: TRR 142 - _id: '55' name: TRR 142 - Project Area B - _id: '66' name: TRR 142 - Subproject B1 - _id: '69' name: TRR 142 - Subproject B4 - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing publication: 'Journal of Physics: Condensed Matter' publication_identifier: eissn: - 1361-648X issn: - 0953-8984 publication_status: published publisher: IOP Publishing quality_controlled: '1' status: public title: Zn–VI quasiparticle gaps and optical spectra from many-body calculations type: journal_article user_id: '16199' volume: 29 year: '2017' ... --- _id: '10024' abstract: - lang: eng text: The influence of electronic many-body interactions, spin-orbit coupling, and thermal lattice vibrations on the electronic structure of lithium niobate is calculated from first principles. Self-energy calculations in the GW approximation show that the inclusion of self-consistency in the Green function G and the screened Coulomb potential W opens the band gap far stronger than found in previous G0W0 calculations but slightly overestimates its actual value due to the neglect of excitonic effects in W. A realistic frozen-lattice band gap of about 5.9 eV is obtained by combining hybrid density functional theory with the QSGW0 scheme. The renormalization of the band gap due to electron-phonon coupling, derived here using molecular dynamics as well as density functional perturbation theory, reduces this value by about 0.5 eV at room temperature. Spin-orbit coupling does not noticeably modify the fundamental gap but gives rise to a Rashba-like spin texture in the conduction band. article_number: '075205' article_type: original author: - first_name: Arthur full_name: Riefer, Arthur last_name: Riefer - first_name: Michael full_name: Friedrich, Michael last_name: Friedrich - first_name: Simone full_name: Sanna, Simone last_name: Sanna - first_name: Uwe full_name: Gerstmann, Uwe id: '171' last_name: Gerstmann orcid: 0000-0002-4476-223X - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X - first_name: Wolf Gero full_name: Schmidt, Wolf Gero id: '468' last_name: Schmidt orcid: 0000-0002-2717-5076 citation: ama: 'Riefer A, Friedrich M, Sanna S, Gerstmann U, Schindlmayr A, Schmidt WG. LiNbO3 electronic structure: Many-body interactions, spin-orbit coupling, and thermal effects. Physical Review B. 2016;93(7). doi:10.1103/PhysRevB.93.075205' apa: 'Riefer, A., Friedrich, M., Sanna, S., Gerstmann, U., Schindlmayr, A., & Schmidt, W. G. (2016). LiNbO3 electronic structure: Many-body interactions, spin-orbit coupling, and thermal effects. Physical Review B, 93(7), Article 075205. https://doi.org/10.1103/PhysRevB.93.075205' bibtex: '@article{Riefer_Friedrich_Sanna_Gerstmann_Schindlmayr_Schmidt_2016, title={LiNbO3 electronic structure: Many-body interactions, spin-orbit coupling, and thermal effects}, volume={93}, DOI={10.1103/PhysRevB.93.075205}, number={7075205}, journal={Physical Review B}, publisher={American Physical Society}, author={Riefer, Arthur and Friedrich, Michael and Sanna, Simone and Gerstmann, Uwe and Schindlmayr, Arno and Schmidt, Wolf Gero}, year={2016} }' chicago: 'Riefer, Arthur, Michael Friedrich, Simone Sanna, Uwe Gerstmann, Arno Schindlmayr, and Wolf Gero Schmidt. “LiNbO3 Electronic Structure: Many-Body Interactions, Spin-Orbit Coupling, and Thermal Effects.” Physical Review B 93, no. 7 (2016). https://doi.org/10.1103/PhysRevB.93.075205.' ieee: 'A. Riefer, M. Friedrich, S. Sanna, U. Gerstmann, A. Schindlmayr, and W. G. Schmidt, “LiNbO3 electronic structure: Many-body interactions, spin-orbit coupling, and thermal effects,” Physical Review B, vol. 93, no. 7, Art. no. 075205, 2016, doi: 10.1103/PhysRevB.93.075205.' mla: 'Riefer, Arthur, et al. “LiNbO3 Electronic Structure: Many-Body Interactions, Spin-Orbit Coupling, and Thermal Effects.” Physical Review B, vol. 93, no. 7, 075205, American Physical Society, 2016, doi:10.1103/PhysRevB.93.075205.' short: A. Riefer, M. Friedrich, S. Sanna, U. Gerstmann, A. Schindlmayr, W.G. Schmidt, Physical Review B 93 (2016). date_created: 2019-05-29T07:50:59Z date_updated: 2025-12-05T09:59:57Z ddc: - '530' department: - _id: '295' - _id: '296' - _id: '230' - _id: '429' - _id: '790' - _id: '15' - _id: '35' - _id: '27' doi: 10.1103/PhysRevB.93.075205 external_id: isi: - '000370794800004' file: - access_level: open_access content_type: application/pdf creator: schindlm date_created: 2020-08-27T20:36:43Z date_updated: 2020-08-30T14:39:23Z description: © 2016 American Physical Society file_id: '18469' file_name: PhysRevB.93.075205.pdf file_size: 1314637 relation: main_file title: 'LiNbO3 electronic structure: Many-body interactions, spin-orbit coupling, and thermal effects' file_date_updated: 2020-08-30T14:39:23Z has_accepted_license: '1' intvolume: ' 93' isi: '1' issue: '7' language: - iso: eng oa: '1' project: - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing - _id: '53' name: TRR 142 - _id: '55' name: TRR 142 - Project Area B - _id: '69' name: TRR 142 - Subproject B4 - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing publication: Physical Review B publication_identifier: eissn: - 2469-9969 issn: - 2469-9950 publication_status: published publisher: American Physical Society quality_controlled: '1' status: public title: 'LiNbO3 electronic structure: Many-body interactions, spin-orbit coupling, and thermal effects' type: journal_article user_id: '16199' volume: 93 year: '2016' ... --- _id: '10025' abstract: - lang: eng text: The phonon dispersions of the ferro‐ and paraelectric phase of LiTaO3 are calculated within density‐functional perturbation theory. The longitudinal optical phonon modes are theoretically derived and compared with available experimental data. Our results confirm the recent phonon assignment proposed by Margueron et al. [J. Appl. Phys. 111, 104105 (2012)] on the basis of spectroscopical studies. A comparison with the phonon band structure of the related material LiNbO3 shows minor differences that can be traced to the atomic‐mass difference between Ta and Nb. The presence of phonons with imaginary frequencies for the paraelectric phase suggests that it does not correspond to a minimum energy structure, and is compatible with an order‐disorder type phase transition. article_type: original author: - first_name: Michael full_name: Friedrich, Michael last_name: Friedrich - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X - first_name: Wolf Gero full_name: Schmidt, Wolf Gero id: '468' last_name: Schmidt orcid: 0000-0002-2717-5076 - first_name: Simone full_name: Sanna, Simone last_name: Sanna citation: ama: Friedrich M, Schindlmayr A, Schmidt WG, Sanna S. LiTaO3 phonon dispersion and ferroelectric transition calculated from first principles. Physica Status Solidi B. 2016;253(4):683-689. doi:10.1002/pssb.201552576 apa: Friedrich, M., Schindlmayr, A., Schmidt, W. G., & Sanna, S. (2016). LiTaO3 phonon dispersion and ferroelectric transition calculated from first principles. Physica Status Solidi B, 253(4), 683–689. https://doi.org/10.1002/pssb.201552576 bibtex: '@article{Friedrich_Schindlmayr_Schmidt_Sanna_2016, title={LiTaO3 phonon dispersion and ferroelectric transition calculated from first principles}, volume={253}, DOI={10.1002/pssb.201552576}, number={4}, journal={Physica Status Solidi B}, publisher={Wiley-VCH}, author={Friedrich, Michael and Schindlmayr, Arno and Schmidt, Wolf Gero and Sanna, Simone}, year={2016}, pages={683–689} }' chicago: 'Friedrich, Michael, Arno Schindlmayr, Wolf Gero Schmidt, and Simone Sanna. “LiTaO3 Phonon Dispersion and Ferroelectric Transition Calculated from First Principles.” Physica Status Solidi B 253, no. 4 (2016): 683–89. https://doi.org/10.1002/pssb.201552576.' ieee: 'M. Friedrich, A. Schindlmayr, W. G. Schmidt, and S. Sanna, “LiTaO3 phonon dispersion and ferroelectric transition calculated from first principles,” Physica Status Solidi B, vol. 253, no. 4, pp. 683–689, 2016, doi: 10.1002/pssb.201552576.' mla: Friedrich, Michael, et al. “LiTaO3 Phonon Dispersion and Ferroelectric Transition Calculated from First Principles.” Physica Status Solidi B, vol. 253, no. 4, Wiley-VCH, 2016, pp. 683–89, doi:10.1002/pssb.201552576. short: M. Friedrich, A. Schindlmayr, W.G. Schmidt, S. Sanna, Physica Status Solidi B 253 (2016) 683–689. date_created: 2019-05-29T07:52:52Z date_updated: 2025-12-05T09:58:55Z ddc: - '530' department: - _id: '295' - _id: '296' - _id: '230' - _id: '429' - _id: '15' - _id: '35' - _id: '27' doi: 10.1002/pssb.201552576 external_id: isi: - '000374142500015' file: - access_level: closed content_type: application/pdf creator: schindlm date_created: 2020-08-28T14:22:11Z date_updated: 2020-08-30T14:41:39Z description: © 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim file_id: '18577' file_name: pssb.201552576.pdf file_size: 402594 relation: main_file title: LiTaO3 phonon dispersion and ferroelectric transition calculated from first principles file_date_updated: 2020-08-30T14:41:39Z has_accepted_license: '1' intvolume: ' 253' isi: '1' issue: '4' language: - iso: eng page: 683-689 project: - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing - _id: '53' name: TRR 142 - _id: '55' name: TRR 142 - Project Area B - _id: '69' name: TRR 142 - Subproject B4 - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing publication: Physica Status Solidi B publication_identifier: eissn: - 1521-3951 issn: - 0370-1972 publication_status: published publisher: Wiley-VCH quality_controlled: '1' status: public title: LiTaO3 phonon dispersion and ferroelectric transition calculated from first principles type: journal_article user_id: '16199' volume: 253 year: '2016' ... --- _id: '10030' abstract: - lang: eng text: The vibrational properties of stoichiometric LiNbO3 are analyzed within density-functional perturbation theory in order to obtain the complete phonon dispersion of the material. The phonon density of states of the ferroelectric (paraelectric) phase shows two (one) distinct band gaps separating the high-frequency (~800 cm−1) optical branches from the continuum of acoustic and lower optical phonon states. This result leads to specific heat capacites in close agreement with experimental measurements in the range 0–350 K and a Debye temperature of 574 K. The calculated zero-point renormalization of the electronic Kohn–Sham eigenvalues reveals a strong dependence on the phonon wave vectors, especially near Γ. Integrated over all phonon modes, our results indicate a vibrational correction of the electronic band gap of 0.41 eV at 0 K, which is in excellent agreement with the extrapolated temperature-dependent measurements. article_number: '385402' article_type: original author: - first_name: Michael full_name: Friedrich, Michael last_name: Friedrich - first_name: Arthur full_name: Riefer, Arthur last_name: Riefer - first_name: Simone full_name: Sanna, Simone last_name: Sanna - first_name: Wolf Gero full_name: Schmidt, Wolf Gero id: '468' last_name: Schmidt orcid: 0000-0002-2717-5076 - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X citation: ama: 'Friedrich M, Riefer A, Sanna S, Schmidt WG, Schindlmayr A. Phonon dispersion and zero-point renormalization of LiNbO3 from density-functional perturbation theory. Journal of Physics: Condensed Matter. 2015;27(38). doi:10.1088/0953-8984/27/38/385402' apa: 'Friedrich, M., Riefer, A., Sanna, S., Schmidt, W. G., & Schindlmayr, A. (2015). Phonon dispersion and zero-point renormalization of LiNbO3 from density-functional perturbation theory. Journal of Physics: Condensed Matter, 27(38), Article 385402. https://doi.org/10.1088/0953-8984/27/38/385402' bibtex: '@article{Friedrich_Riefer_Sanna_Schmidt_Schindlmayr_2015, title={Phonon dispersion and zero-point renormalization of LiNbO3 from density-functional perturbation theory}, volume={27}, DOI={10.1088/0953-8984/27/38/385402}, number={38385402}, journal={Journal of Physics: Condensed Matter}, publisher={IOP Publishing}, author={Friedrich, Michael and Riefer, Arthur and Sanna, Simone and Schmidt, Wolf Gero and Schindlmayr, Arno}, year={2015} }' chicago: 'Friedrich, Michael, Arthur Riefer, Simone Sanna, Wolf Gero Schmidt, and Arno Schindlmayr. “Phonon Dispersion and Zero-Point Renormalization of LiNbO3 from Density-Functional Perturbation Theory.” Journal of Physics: Condensed Matter 27, no. 38 (2015). https://doi.org/10.1088/0953-8984/27/38/385402.' ieee: 'M. Friedrich, A. Riefer, S. Sanna, W. G. Schmidt, and A. Schindlmayr, “Phonon dispersion and zero-point renormalization of LiNbO3 from density-functional perturbation theory,” Journal of Physics: Condensed Matter, vol. 27, no. 38, Art. no. 385402, 2015, doi: 10.1088/0953-8984/27/38/385402.' mla: 'Friedrich, Michael, et al. “Phonon Dispersion and Zero-Point Renormalization of LiNbO3 from Density-Functional Perturbation Theory.” Journal of Physics: Condensed Matter, vol. 27, no. 38, 385402, IOP Publishing, 2015, doi:10.1088/0953-8984/27/38/385402.' short: 'M. Friedrich, A. Riefer, S. Sanna, W.G. Schmidt, A. Schindlmayr, Journal of Physics: Condensed Matter 27 (2015).' date_created: 2019-05-29T08:41:18Z date_updated: 2025-12-05T10:00:42Z ddc: - '530' department: - _id: '295' - _id: '296' - _id: '230' - _id: '429' - _id: '15' - _id: '35' - _id: '27' doi: 10.1088/0953-8984/27/38/385402 external_id: isi: - '000362549700004' pmid: - '26337951' file: - access_level: closed content_type: application/pdf creator: schindlm date_created: 2020-08-28T14:24:23Z date_updated: 2020-08-30T14:46:56Z description: © 2015 IOP Publishing Ltd file_id: '18578' file_name: Friedrich_2015_J._Phys. _Condens._Matter_27_385402.pdf file_size: 1793430 relation: main_file title: Phonon dispersion and zero-point renormalization of LiNbO3 from density-functional perturbation theory file_date_updated: 2020-08-30T14:46:56Z has_accepted_license: '1' intvolume: ' 27' isi: '1' issue: '38' language: - iso: eng pmid: '1' project: - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing - _id: '53' name: TRR 142 - _id: '55' name: TRR 142 - Project Area B - _id: '69' name: TRR 142 - Subproject B4 - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing publication: 'Journal of Physics: Condensed Matter' publication_identifier: eissn: - 1361-648X issn: - 0953-8984 publication_status: published publisher: IOP Publishing quality_controlled: '1' status: public title: Phonon dispersion and zero-point renormalization of LiNbO3 from density-functional perturbation theory type: journal_article user_id: '16199' volume: 27 year: '2015' ... --- _id: '18470' abstract: - lang: eng text: Using ab initio computational methods, we study the structural and electronic properties of strained silicon, which has emerged as a promising technology to improve the performance of silicon-based metal-oxide-semiconductor field-effect transistors. In particular, higher electron mobilities are observed in n-doped samples with monoclinic strain along the [110] direction, and experimental evidence relates this to changes in the effective mass as well as the scattering rates. To assess the relative importance of these two factors, we combine density-functional theory in the local-density approximation with the GW approximation for the electronic self-energy and investigate the effect of uniaxial and biaxial strains along the [110] direction on the structural and electronic properties of Si. Longitudinal and transverse components of the electron effective mass as a function of the strain are derived from fits to the quasiparticle band structure and a diagonalization of the full effective-mass tensor. The changes in the effective masses and the energy splitting of the conduction-band valleys for uniaxial and biaxial strains as well as their impact on the electron mobility are analyzed. The self-energy corrections within GW lead to band gaps in excellent agreement with experimental measurements and slightly larger effective masses than in the local-density approximation. article_number: '453125' article_type: original author: - first_name: Mohammed full_name: Bouhassoune, Mohammed last_name: Bouhassoune - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X citation: ama: Bouhassoune M, Schindlmayr A. Ab initio study of strain effects on the quasiparticle bands and effective masses in silicon. Advances in Condensed Matter Physics. 2015;2015. doi:10.1155/2015/453125 apa: Bouhassoune, M., & Schindlmayr, A. (2015). Ab initio study of strain effects on the quasiparticle bands and effective masses in silicon. Advances in Condensed Matter Physics, 2015, Article 453125. https://doi.org/10.1155/2015/453125 bibtex: '@article{Bouhassoune_Schindlmayr_2015, title={Ab initio study of strain effects on the quasiparticle bands and effective masses in silicon}, volume={2015}, DOI={10.1155/2015/453125}, number={453125}, journal={Advances in Condensed Matter Physics}, publisher={Hindawi}, author={Bouhassoune, Mohammed and Schindlmayr, Arno}, year={2015} }' chicago: Bouhassoune, Mohammed, and Arno Schindlmayr. “Ab Initio Study of Strain Effects on the Quasiparticle Bands and Effective Masses in Silicon.” Advances in Condensed Matter Physics 2015 (2015). https://doi.org/10.1155/2015/453125. ieee: 'M. Bouhassoune and A. Schindlmayr, “Ab initio study of strain effects on the quasiparticle bands and effective masses in silicon,” Advances in Condensed Matter Physics, vol. 2015, Art. no. 453125, 2015, doi: 10.1155/2015/453125.' mla: Bouhassoune, Mohammed, and Arno Schindlmayr. “Ab Initio Study of Strain Effects on the Quasiparticle Bands and Effective Masses in Silicon.” Advances in Condensed Matter Physics, vol. 2015, 453125, Hindawi, 2015, doi:10.1155/2015/453125. short: M. Bouhassoune, A. Schindlmayr, Advances in Condensed Matter Physics 2015 (2015). date_created: 2020-08-27T20:45:37Z date_updated: 2025-12-16T11:08:01Z ddc: - '530' department: - _id: '296' - _id: '35' - _id: '15' - _id: '170' - _id: '230' doi: 10.1155/2015/453125 external_id: isi: - '000350656500001' file: - access_level: open_access content_type: application/pdf creator: schindlm date_created: 2020-08-28T09:42:44Z date_updated: 2020-08-30T14:45:29Z description: Creative Commons Attribution 3.0 Unported Public License (CC BY 3.0) file_id: '18540' file_name: 453125.pdf file_size: 560248 relation: main_file title: Ab initio study of strain effects on the quasiparticle bands and effective masses in silicon file_date_updated: 2020-08-30T14:45:29Z has_accepted_license: '1' intvolume: ' 2015' isi: '1' language: - iso: eng oa: '1' publication: Advances in Condensed Matter Physics publication_identifier: eissn: - 1687-8124 issn: - 1687-8108 publication_status: published publisher: Hindawi quality_controlled: '1' status: public title: Ab initio study of strain effects on the quasiparticle bands and effective masses in silicon type: journal_article user_id: '16199' volume: 2015 year: '2015' ... --- _id: '18471' abstract: - lang: eng text: Collective spin excitations form a fundamental class of excitations in magnetic materials. As their energy reaches down to only a few meV, they are present at all temperatures and substantially influence the properties of magnetic systems. To study the spin excitations in solids from first principles, we have developed a computational scheme based on many-body perturbation theory within the full-potential linearized augmented plane-wave (FLAPW) method. The main quantity of interest is the dynamical transverse spin susceptibility or magnetic response function, from which magnetic excitations, including single-particle spin-flip Stoner excitations and collective spin-wave modes as well as their lifetimes, can be obtained. In order to describe spin waves we include appropriate vertex corrections in the form of a multiple-scattering T matrix, which describes the coupling of electrons and holes with different spins. The electron–hole interaction incorporates the screening of the many-body system within the random-phase approximation. To reduce the numerical cost in evaluating the four-point T matrix, we exploit a transformation to maximally localized Wannier functions that takes advantage of the short spatial range of electronic correlation in the partially filled d or f orbitals of magnetic materials. The theory and the implementation are discussed in detail. In particular, we show how the magnetic response function can be evaluated for arbitrary k points. This enables the calculation of smooth dispersion curves, allowing one to study fine details in the k dependence of the spin-wave spectra. We also demonstrate how spatial and time-reversal symmetry can be exploited to accelerate substantially the computation of the four-point quantities. As an illustration, we present spin-wave spectra and dispersions for the elementary ferromagnet bcc Fe, B2-type tetragonal FeCo, and CrO2 calculated with our scheme. The results are in good agreement with available experimental data. author: - first_name: Christoph full_name: Friedrich, Christoph last_name: Friedrich - first_name: Ersoy full_name: Şaşıoğlu, Ersoy last_name: Şaşıoğlu - first_name: Mathias full_name: Müller, Mathias last_name: Müller - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X - first_name: Stefan full_name: Blügel, Stefan last_name: Blügel citation: ama: 'Friedrich C, Şaşıoğlu E, Müller M, Schindlmayr A, Blügel S. Spin excitations in solids from many-body perturbation theory. In: Di Valentin C, Botti S, Cococcioni M, eds. First Principles Approaches to Spectroscopic Properties of Complex Materials. Vol 347. Topics in Current Chemistry. Springer; 2014:259-301. doi:10.1007/128_2013_518' apa: Friedrich, C., Şaşıoğlu, E., Müller, M., Schindlmayr, A., & Blügel, S. (2014). Spin excitations in solids from many-body perturbation theory. In C. Di Valentin, S. Botti, & M. Cococcioni (Eds.), First Principles Approaches to Spectroscopic Properties of Complex Materials (Vol. 347, pp. 259–301). Springer. https://doi.org/10.1007/128_2013_518 bibtex: '@inbook{Friedrich_Şaşıoğlu_Müller_Schindlmayr_Blügel_2014, place={Berlin, Heidelberg}, series={ Topics in Current Chemistry}, title={Spin excitations in solids from many-body perturbation theory}, volume={347}, DOI={10.1007/128_2013_518}, booktitle={First Principles Approaches to Spectroscopic Properties of Complex Materials}, publisher={Springer}, author={Friedrich, Christoph and Şaşıoğlu, Ersoy and Müller, Mathias and Schindlmayr, Arno and Blügel, Stefan}, editor={Di Valentin, Cristiana and Botti, Silvana and Cococcioni, Matteo}, year={2014}, pages={259–301}, collection={ Topics in Current Chemistry} }' chicago: 'Friedrich, Christoph, Ersoy Şaşıoğlu, Mathias Müller, Arno Schindlmayr, and Stefan Blügel. “Spin Excitations in Solids from Many-Body Perturbation Theory.” In First Principles Approaches to Spectroscopic Properties of Complex Materials, edited by Cristiana Di Valentin, Silvana Botti, and Matteo Cococcioni, 347:259–301. Topics in Current Chemistry. Berlin, Heidelberg: Springer, 2014. https://doi.org/10.1007/128_2013_518.' ieee: 'C. Friedrich, E. Şaşıoğlu, M. Müller, A. Schindlmayr, and S. Blügel, “Spin excitations in solids from many-body perturbation theory,” in First Principles Approaches to Spectroscopic Properties of Complex Materials, vol. 347, C. Di Valentin, S. Botti, and M. Cococcioni, Eds. Berlin, Heidelberg: Springer, 2014, pp. 259–301.' mla: Friedrich, Christoph, et al. “Spin Excitations in Solids from Many-Body Perturbation Theory.” First Principles Approaches to Spectroscopic Properties of Complex Materials, edited by Cristiana Di Valentin et al., vol. 347, Springer, 2014, pp. 259–301, doi:10.1007/128_2013_518. short: 'C. Friedrich, E. Şaşıoğlu, M. Müller, A. Schindlmayr, S. Blügel, in: C. Di Valentin, S. Botti, M. Cococcioni (Eds.), First Principles Approaches to Spectroscopic Properties of Complex Materials, Springer, Berlin, Heidelberg, 2014, pp. 259–301.' date_created: 2020-08-27T21:00:45Z date_updated: 2025-12-16T08:06:12Z ddc: - '530' department: - _id: '296' - _id: '35' - _id: '15' - _id: '230' doi: 10.1007/128_2013_518 editor: - first_name: Cristiana full_name: Di Valentin, Cristiana last_name: Di Valentin - first_name: Silvana full_name: Botti, Silvana last_name: Botti - first_name: Matteo full_name: Cococcioni, Matteo last_name: Cococcioni external_id: isi: - '000356811000008' pmid: - '24577607' file: - access_level: closed content_type: application/pdf creator: schindlm date_created: 2020-08-28T15:19:57Z date_updated: 2020-08-30T14:48:45Z description: © 2014 Springer-Verlag, Berlin, Heidelberg file_id: '18584' file_name: Friedrich2014_Chapter_SpinExcitationsInSolidsFromMan.pdf file_size: 1061365 relation: main_file title: Spin excitations in solids from many-body perturbation theory file_date_updated: 2020-08-30T14:48:45Z has_accepted_license: '1' intvolume: ' 347' isi: '1' language: - iso: eng page: 259-301 place: Berlin, Heidelberg pmid: '1' publication: First Principles Approaches to Spectroscopic Properties of Complex Materials publication_identifier: eisbn: - 978-3-642-55068-3 eissn: - 1436-5049 isbn: - 978-3-642-55067-6 issn: - 0340-1022 publication_status: published publisher: Springer quality_controlled: '1' series_title: ' Topics in Current Chemistry' status: public title: Spin excitations in solids from many-body perturbation theory type: book_chapter user_id: '16199' volume: 347 year: '2014' ... --- _id: '18472' abstract: - lang: eng text: Many-body perturbation theory is a well-established ab initio electronic-structure method based on Green functions. Although computationally more demanding than density functional theory, it has the distinct advantage that the exact expressions for all relevant observables, including the ground-state total energy, in terms of the Green function are known explicitly. The most important application, however, lies in the calculation of excited states, whose energies correspond directly to the poles of the Green function in the complex frequency plane. The accuracy of results obtained within this framework is only limited by the choice of the exchange-correlation self-energy, which must still be approximated in actual implementations. In this respect, the GW approximation has proved highly successful for systems governed by the Coulomb interaction. It yields band structures of solids, including the band gaps of semiconductors, as well as atomic and molecular ionization energies in very good quantitative agreement with experimental photoemission data. author: - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X citation: ama: 'Schindlmayr A. The GW approximation for the electronic self-energy. In: Bach V, Delle Site L, eds. Many-Electron Approaches in Physics, Chemistry and Mathematics. Vol 29. Mathematical Physics Studies. Springer; 2014:343-357. doi:10.1007/978-3-319-06379-9_19' apa: Schindlmayr, A. (2014). The GW approximation for the electronic self-energy. In V. Bach & L. Delle Site (Eds.), Many-Electron Approaches in Physics, Chemistry and Mathematics (Vol. 29, pp. 343–357). Springer. https://doi.org/10.1007/978-3-319-06379-9_19 bibtex: '@inbook{Schindlmayr_2014, place={Cham}, series={ Mathematical Physics Studies}, title={The GW approximation for the electronic self-energy}, volume={29}, DOI={10.1007/978-3-319-06379-9_19}, booktitle={Many-Electron Approaches in Physics, Chemistry and Mathematics}, publisher={Springer}, author={Schindlmayr, Arno}, editor={Bach, Volker and Delle Site, Luigi}, year={2014}, pages={343–357}, collection={ Mathematical Physics Studies} }' chicago: 'Schindlmayr, Arno. “The GW Approximation for the Electronic Self-Energy.” In Many-Electron Approaches in Physics, Chemistry and Mathematics, edited by Volker Bach and Luigi Delle Site, 29:343–57. Mathematical Physics Studies. Cham: Springer, 2014. https://doi.org/10.1007/978-3-319-06379-9_19.' ieee: 'A. Schindlmayr, “The GW approximation for the electronic self-energy,” in Many-Electron Approaches in Physics, Chemistry and Mathematics, vol. 29, V. Bach and L. Delle Site, Eds. Cham: Springer, 2014, pp. 343–357.' mla: Schindlmayr, Arno. “The GW Approximation for the Electronic Self-Energy.” Many-Electron Approaches in Physics, Chemistry and Mathematics, edited by Volker Bach and Luigi Delle Site, vol. 29, Springer, 2014, pp. 343–57, doi:10.1007/978-3-319-06379-9_19. short: 'A. Schindlmayr, in: V. Bach, L. Delle Site (Eds.), Many-Electron Approaches in Physics, Chemistry and Mathematics, Springer, Cham, 2014, pp. 343–357.' date_created: 2020-08-27T21:11:43Z date_updated: 2025-12-16T08:05:25Z ddc: - '530' department: - _id: '296' - _id: '35' - _id: '15' - _id: '170' - _id: '230' doi: 10.1007/978-3-319-06379-9_19 editor: - first_name: Volker full_name: Bach, Volker last_name: Bach - first_name: Luigi full_name: Delle Site, Luigi last_name: Delle Site file: - access_level: closed content_type: application/pdf creator: schindlm date_created: 2020-08-28T15:25:10Z date_updated: 2020-08-30T14:50:18Z description: © 2014 Springer International Publishing, Switzerland file_id: '18585' file_name: Schindlmayr2014_Chapter_TheGWApproximationForTheElectr.pdf file_size: 309579 relation: main_file title: The GW approximation for the electronic self-energy file_date_updated: 2020-08-30T14:50:18Z has_accepted_license: '1' intvolume: ' 29' language: - iso: eng page: 343-357 place: Cham publication: Many-Electron Approaches in Physics, Chemistry and Mathematics publication_identifier: eisbn: - 978-3-319-06379-9 eissn: - 2352-3905 isbn: - 978-3-319-06378-2 issn: - 0921-3767 publication_status: published publisher: Springer quality_controlled: '1' series_title: ' Mathematical Physics Studies' status: public title: The GW approximation for the electronic self-energy type: book_chapter user_id: '16199' volume: 29 year: '2014' ... --- _id: '18473' abstract: - lang: eng text: We investigate the band dispersion and related electronic properties of picene single crystals within the GW approximation for the electronic self-energy. The width of the upper highest occupied molecular orbital (HOMOu) band along the Γ–Y direction, corresponding to the b crystal axis in real space along which the molecules are stacked, is determined to be 0.60 eV and thus 0.11 eV larger than the value obtained from density-functional theory. As in our recent study of rubrene using the same methodology [S. Yanagisawa, Y. Morikawa, and A. Schindlmayr, Phys. Rev. B 88, 115438 (2013)], this increase in the bandwidth is due to the strong variation of the GW self-energy correction across the Brillouin zone, which in turn reflects the increasing hybridization of the HOMOu states of neighboring picene molecules from Γ to Y. In contrast, the width of the lower HOMO (HOMOl) band along Γ–Y remains almost unchanged, consistent with the fact that the HOMOl(Γ) and HOMOl(Y) states exhibit the same degree of hybridization, so that the nodal structure of the wave functions and the matrix elements of the self-energy correction are very similar. article_number: 05FY02 article_type: original author: - first_name: Susumu full_name: Yanagisawa, Susumu last_name: Yanagisawa - first_name: Yoshitada full_name: Morikawa, Yoshitada last_name: Morikawa - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X citation: ama: Yanagisawa S, Morikawa Y, Schindlmayr A. Theoretical investigation of the band structure of picene single crystals within the GW approximation. Japanese Journal of Applied Physics. 2014;53(5S1). doi:10.7567/jjap.53.05fy02 apa: Yanagisawa, S., Morikawa, Y., & Schindlmayr, A. (2014). Theoretical investigation of the band structure of picene single crystals within the GW approximation. Japanese Journal of Applied Physics, 53(5S1), Article 05FY02. https://doi.org/10.7567/jjap.53.05fy02 bibtex: '@article{Yanagisawa_Morikawa_Schindlmayr_2014, title={Theoretical investigation of the band structure of picene single crystals within the GW approximation}, volume={53}, DOI={10.7567/jjap.53.05fy02}, number={5S105FY02}, journal={Japanese Journal of Applied Physics}, publisher={IOP Publishing and The Japan Society of Applied Physics}, author={Yanagisawa, Susumu and Morikawa, Yoshitada and Schindlmayr, Arno}, year={2014} }' chicago: Yanagisawa, Susumu, Yoshitada Morikawa, and Arno Schindlmayr. “Theoretical Investigation of the Band Structure of Picene Single Crystals within the GW Approximation.” Japanese Journal of Applied Physics 53, no. 5S1 (2014). https://doi.org/10.7567/jjap.53.05fy02. ieee: 'S. Yanagisawa, Y. Morikawa, and A. Schindlmayr, “Theoretical investigation of the band structure of picene single crystals within the GW approximation,” Japanese Journal of Applied Physics, vol. 53, no. 5S1, Art. no. 05FY02, 2014, doi: 10.7567/jjap.53.05fy02.' mla: Yanagisawa, Susumu, et al. “Theoretical Investigation of the Band Structure of Picene Single Crystals within the GW Approximation.” Japanese Journal of Applied Physics, vol. 53, no. 5S1, 05FY02, IOP Publishing and The Japan Society of Applied Physics, 2014, doi:10.7567/jjap.53.05fy02. short: S. Yanagisawa, Y. Morikawa, A. Schindlmayr, Japanese Journal of Applied Physics 53 (2014). date_created: 2020-08-27T21:21:24Z date_updated: 2025-12-16T08:04:51Z ddc: - '530' department: - _id: '296' - _id: '35' - _id: '15' - _id: '170' - _id: '230' doi: 10.7567/jjap.53.05fy02 external_id: isi: - '000338316200158' file: - access_level: closed content_type: application/pdf creator: schindlm date_created: 2020-08-28T14:28:20Z date_updated: 2020-08-30T14:52:27Z description: © 2014 The Japan Society of Applied Physics file_id: '18579' file_name: Yanagisawa_2014_Jpn._J._Appl._Phys._53_05FY02.pdf file_size: 588607 relation: main_file title: Theoretical investigation of the band structure of picene single crystals within the GW approximation file_date_updated: 2020-08-30T14:52:27Z has_accepted_license: '1' intvolume: ' 53' isi: '1' issue: 5S1 language: - iso: eng publication: Japanese Journal of Applied Physics publication_identifier: eissn: - 1347-4065 issn: - 0021-4922 publication_status: published publisher: IOP Publishing and The Japan Society of Applied Physics quality_controlled: '1' status: public title: Theoretical investigation of the band structure of picene single crystals within the GW approximation type: journal_article user_id: '16199' volume: 53 year: '2014' ... --- _id: '18474' author: - first_name: Christoph full_name: Friedrich, Christoph last_name: Friedrich - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X citation: ama: 'Friedrich C, Schindlmayr A. Many-body perturbation theory: The GW approximation. In: Blügel S, Helbig N, Meden V, Wortmann D, eds. Computing Solids: Models, Ab Initio Methods and Supercomputing. Vol 74. Key Technologies. Forschungszentrum Jülich; 2014:A4.1-A4.21.' apa: 'Friedrich, C., & Schindlmayr, A. (2014). Many-body perturbation theory: The GW approximation. In S. Blügel, N. Helbig, V. Meden, & D. Wortmann (Eds.), Computing Solids: Models, ab initio Methods and Supercomputing (Vol. 74, p. A4.1-A4.21). Forschungszentrum Jülich.' bibtex: '@inbook{Friedrich_Schindlmayr_2014, place={Jülich}, series={Key Technologies}, title={Many-body perturbation theory: The GW approximation}, volume={74}, booktitle={Computing Solids: Models, ab initio Methods and Supercomputing}, publisher={Forschungszentrum Jülich}, author={Friedrich, Christoph and Schindlmayr, Arno}, editor={Blügel, Stefan and Helbig, Nicole and Meden, Volker and Wortmann, Daniel}, year={2014}, pages={A4.1-A4.21}, collection={Key Technologies} }' chicago: 'Friedrich, Christoph, and Arno Schindlmayr. “Many-Body Perturbation Theory: The GW Approximation.” In Computing Solids: Models, Ab Initio Methods and Supercomputing, edited by Stefan Blügel, Nicole Helbig, Volker Meden, and Daniel Wortmann, 74:A4.1-A4.21. Key Technologies. Jülich: Forschungszentrum Jülich, 2014.' ieee: 'C. Friedrich and A. Schindlmayr, “Many-body perturbation theory: The GW approximation,” in Computing Solids: Models, ab initio Methods and Supercomputing, vol. 74, S. Blügel, N. Helbig, V. Meden, and D. Wortmann, Eds. Jülich: Forschungszentrum Jülich, 2014, p. A4.1-A4.21.' mla: 'Friedrich, Christoph, and Arno Schindlmayr. “Many-Body Perturbation Theory: The GW Approximation.” Computing Solids: Models, Ab Initio Methods and Supercomputing, edited by Stefan Blügel et al., vol. 74, Forschungszentrum Jülich, 2014, p. A4.1-A4.21.' short: 'C. Friedrich, A. Schindlmayr, in: S. Blügel, N. Helbig, V. Meden, D. Wortmann (Eds.), Computing Solids: Models, Ab Initio Methods and Supercomputing, Forschungszentrum Jülich, Jülich, 2014, p. A4.1-A4.21.' conference: end_date: 2014-03-21 location: Jülich name: 45th Spring School of the Institute of Solid State Research start_date: 2014-03-10 date_created: 2020-08-27T21:40:39Z date_updated: 2025-12-16T08:07:31Z ddc: - '530' department: - _id: '296' - _id: '35' - _id: '15' - _id: '170' - _id: '230' editor: - first_name: Stefan full_name: Blügel, Stefan last_name: Blügel - first_name: Nicole full_name: Helbig, Nicole last_name: Helbig - first_name: Volker full_name: Meden, Volker last_name: Meden - first_name: Daniel full_name: Wortmann, Daniel last_name: Wortmann file: - access_level: request content_type: application/pdf creator: schindlm date_created: 2020-10-05T10:57:49Z date_updated: 2022-01-06T06:53:34Z description: © 2014 Forschungszentrum Jülich file_id: '19876' file_name: A4-Friedrich.pdf file_size: 718521 relation: main_file title: 'Many-body perturbation theory: The GW approximation' file_date_updated: 2022-01-06T06:53:34Z has_accepted_license: '1' intvolume: ' 74' language: - iso: eng main_file_link: - open_access: '1' url: http://hdl.handle.net/2128/8540 oa: '1' page: A4.1-A4.21 place: Jülich publication: 'Computing Solids: Models, ab initio Methods and Supercomputing' publication_identifier: isbn: - 978-3-89336-912-6 issn: - 1866-1807 publication_status: published publisher: Forschungszentrum Jülich series_title: Key Technologies status: public title: 'Many-body perturbation theory: The GW approximation' type: book_chapter user_id: '16199' volume: 74 year: '2014' ... --- _id: '13525' abstract: - lang: eng text: The frequency-dependent dielectric function and the second-order polarizability tensor of ferroelectric LiNbO3 are calculated from first principles. The calculations are based on the electronic structure obtained from density-functional theory. The subsequent application of the GW approximation to account for quasiparticle effects and the solution of the Bethe-Salpeter equation for the stoichiometric material yield a dielectric function that slightly overestimates the absorption onset and the oscillator strength in comparison with experimental measurements. Calculations at the level of the independent-particle approximation indicate that these deficiencies are, at least, partially related to the neglect of intrinsic defects typical for the congruent material. The second-order polarizability calculated within the independent-particle approximation predicts strong nonlinear coefficients for photon energies above 1.5 eV. The comparison with measured data suggests that the inclusion of self-energy effects in the nonlinear optical response leads to a better agreement with experiments. The intrinsic defects of congruent samples reduce the optical nonlinearities, in particular, for the 21 and 31 tensor components, further improving the agreement between experiments and theory. article_number: '195208' article_type: original author: - first_name: Arthur full_name: Riefer, Arthur last_name: Riefer - first_name: Simone full_name: Sanna, Simone last_name: Sanna - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X - first_name: Wolf Gero full_name: Schmidt, Wolf Gero id: '468' last_name: Schmidt orcid: 0000-0002-2717-5076 citation: ama: Riefer A, Sanna S, Schindlmayr A, Schmidt WG. Optical response of stoichiometric and congruent lithium niobate from first-principles calculations. Physical Review B. 2013;87(19). doi:10.1103/PhysRevB.87.195208 apa: Riefer, A., Sanna, S., Schindlmayr, A., & Schmidt, W. G. (2013). Optical response of stoichiometric and congruent lithium niobate from first-principles calculations. Physical Review B, 87(19), Article 195208. https://doi.org/10.1103/PhysRevB.87.195208 bibtex: '@article{Riefer_Sanna_Schindlmayr_Schmidt_2013, title={Optical response of stoichiometric and congruent lithium niobate from first-principles calculations}, volume={87}, DOI={10.1103/PhysRevB.87.195208}, number={19195208}, journal={Physical Review B}, publisher={American Physical Society}, author={Riefer, Arthur and Sanna, Simone and Schindlmayr, Arno and Schmidt, Wolf Gero}, year={2013} }' chicago: Riefer, Arthur, Simone Sanna, Arno Schindlmayr, and Wolf Gero Schmidt. “Optical Response of Stoichiometric and Congruent Lithium Niobate from First-Principles Calculations.” Physical Review B 87, no. 19 (2013). https://doi.org/10.1103/PhysRevB.87.195208. ieee: 'A. Riefer, S. Sanna, A. Schindlmayr, and W. G. Schmidt, “Optical response of stoichiometric and congruent lithium niobate from first-principles calculations,” Physical Review B, vol. 87, no. 19, Art. no. 195208, 2013, doi: 10.1103/PhysRevB.87.195208.' mla: Riefer, Arthur, et al. “Optical Response of Stoichiometric and Congruent Lithium Niobate from First-Principles Calculations.” Physical Review B, vol. 87, no. 19, 195208, American Physical Society, 2013, doi:10.1103/PhysRevB.87.195208. short: A. Riefer, S. Sanna, A. Schindlmayr, W.G. Schmidt, Physical Review B 87 (2013). date_created: 2019-09-30T14:11:18Z date_updated: 2025-12-05T10:51:45Z ddc: - '530' department: - _id: '295' - _id: '296' - _id: '15' - _id: '35' - _id: '230' - _id: '27' doi: 10.1103/PhysRevB.87.195208 external_id: isi: - '000319391000002' file: - access_level: open_access content_type: application/pdf creator: schindlm date_created: 2020-08-27T22:06:46Z date_updated: 2020-08-30T14:53:40Z description: © 2013 American Physical Society file_id: '18478' file_name: PhysRevB.87.195208.pdf file_size: 791961 relation: main_file title: Optical response of stoichiometric and congruent lithium niobate from first-principles calculations file_date_updated: 2020-08-30T14:53:40Z has_accepted_license: '1' intvolume: ' 87' isi: '1' issue: '19' language: - iso: eng oa: '1' project: - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing publication: Physical Review B publication_identifier: eissn: - 1550-235X issn: - 1098-0121 publication_status: published publisher: American Physical Society quality_controlled: '1' status: public title: Optical response of stoichiometric and congruent lithium niobate from first-principles calculations type: journal_article user_id: '16199' volume: 87 year: '2013' ... --- _id: '18475' abstract: - lang: eng text: The frequency-dependent dielectric function and the second-order polarizability tensor of ferroelectric LiNbO3 are calculated from first principles. The calculations are based on the electronic structure obtained from density-functional theory. The subsequent application of the GW approximation to account for quasiparticle effects and the solution of the Bethe–Salpeter equation yield a dielectric function for the stoichiometric material that slightly overestimates the absorption onset and the oscillator strength in comparison with experimental measurements. Calculations at the level of the independent-particle approximation indicate that these deficiencies are at least partially related to the neglect of intrinsic defects typical for the congruent material. The second-order polarizability calculated within the independent-particle approximation predicts strong nonlinear coefficients for photon energies above 1.5 eV. The comparison with measured data suggests that self-energy effects improve the agreement between experiment and theory. The intrinsic defects of congruent samples reduce the optical nonlinearities, in particular for the 21 and 31 tensor components, further improving the agreement with measured data. author: - first_name: Arthur full_name: Riefer, Arthur last_name: Riefer - first_name: Martin full_name: Rohrmüller, Martin last_name: Rohrmüller - first_name: Marc full_name: Landmann, Marc last_name: Landmann - first_name: Simone full_name: Sanna, Simone last_name: Sanna - first_name: Eva full_name: Rauls, Eva last_name: Rauls - first_name: Nora Jenny full_name: Vollmers, Nora Jenny last_name: Vollmers - first_name: Rebecca full_name: Hölscher, Rebecca last_name: Hölscher - first_name: Matthias full_name: Witte, Matthias last_name: Witte - first_name: Yanlu full_name: Li, Yanlu last_name: Li - first_name: Uwe full_name: Gerstmann, Uwe id: '171' last_name: Gerstmann orcid: 0000-0002-4476-223X - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X - first_name: Wolf Gero full_name: Schmidt, Wolf Gero id: '468' last_name: Schmidt orcid: 0000-0002-2717-5076 citation: ama: 'Riefer A, Rohrmüller M, Landmann M, et al. Lithium niobate dielectric function and second-order polarizability tensor from massively parallel ab initio calculations. In: Nagel WE, Kröner DH, Resch MM, eds. High Performance Computing in Science and Engineering ‘13. Transactions of the High Performance Computing Center, Stuttgart. Springer; 2013:93-104. doi:10.1007/978-3-319-02165-2_8' apa: Riefer, A., Rohrmüller, M., Landmann, M., Sanna, S., Rauls, E., Vollmers, N. J., Hölscher, R., Witte, M., Li, Y., Gerstmann, U., Schindlmayr, A., & Schmidt, W. G. (2013). Lithium niobate dielectric function and second-order polarizability tensor from massively parallel ab initio calculations. In W. E. Nagel, D. H. Kröner, & M. M. Resch (Eds.), High Performance Computing in Science and Engineering ‘13 (pp. 93–104). Springer. https://doi.org/10.1007/978-3-319-02165-2_8 bibtex: '@inbook{Riefer_Rohrmüller_Landmann_Sanna_Rauls_Vollmers_Hölscher_Witte_Li_Gerstmann_et al._2013, place={Cham}, series={Transactions of the High Performance Computing Center, Stuttgart}, title={Lithium niobate dielectric function and second-order polarizability tensor from massively parallel ab initio calculations}, DOI={10.1007/978-3-319-02165-2_8}, booktitle={High Performance Computing in Science and Engineering ‘13}, publisher={Springer}, author={Riefer, Arthur and Rohrmüller, Martin and Landmann, Marc and Sanna, Simone and Rauls, Eva and Vollmers, Nora Jenny and Hölscher, Rebecca and Witte, Matthias and Li, Yanlu and Gerstmann, Uwe and et al.}, editor={Nagel, Wolfgang E. and Kröner, Dietmar H. and Resch, Michael M.}, year={2013}, pages={93–104}, collection={Transactions of the High Performance Computing Center, Stuttgart} }' chicago: 'Riefer, Arthur, Martin Rohrmüller, Marc Landmann, Simone Sanna, Eva Rauls, Nora Jenny Vollmers, Rebecca Hölscher, et al. “Lithium Niobate Dielectric Function and Second-Order Polarizability Tensor from Massively Parallel Ab Initio Calculations.” In High Performance Computing in Science and Engineering ‘13, edited by Wolfgang E. Nagel, Dietmar H. Kröner, and Michael M. Resch, 93–104. Transactions of the High Performance Computing Center, Stuttgart. Cham: Springer, 2013. https://doi.org/10.1007/978-3-319-02165-2_8.' ieee: 'A. Riefer et al., “Lithium niobate dielectric function and second-order polarizability tensor from massively parallel ab initio calculations,” in High Performance Computing in Science and Engineering ‘13, W. E. Nagel, D. H. Kröner, and M. M. Resch, Eds. Cham: Springer, 2013, pp. 93–104.' mla: Riefer, Arthur, et al. “Lithium Niobate Dielectric Function and Second-Order Polarizability Tensor from Massively Parallel Ab Initio Calculations.” High Performance Computing in Science and Engineering ‘13, edited by Wolfgang E. Nagel et al., Springer, 2013, pp. 93–104, doi:10.1007/978-3-319-02165-2_8. short: 'A. Riefer, M. Rohrmüller, M. Landmann, S. Sanna, E. Rauls, N.J. Vollmers, R. Hölscher, M. Witte, Y. Li, U. Gerstmann, A. Schindlmayr, W.G. Schmidt, in: W.E. Nagel, D.H. Kröner, M.M. Resch (Eds.), High Performance Computing in Science and Engineering ‘13, Springer, Cham, 2013, pp. 93–104.' date_created: 2020-08-27T21:48:43Z date_updated: 2025-12-16T08:07:02Z ddc: - '530' department: - _id: '296' - _id: '295' - _id: '35' - _id: '15' - _id: '170' - _id: '790' - _id: '230' - _id: '27' doi: 10.1007/978-3-319-02165-2_8 editor: - first_name: Wolfgang E. full_name: Nagel, Wolfgang E. last_name: Nagel - first_name: Dietmar H. full_name: Kröner, Dietmar H. last_name: Kröner - first_name: Michael M. full_name: Resch, Michael M. last_name: Resch external_id: isi: - '000360004100009' file: - access_level: closed content_type: application/pdf creator: schindlm date_created: 2020-08-28T15:34:44Z date_updated: 2020-08-30T14:57:36Z description: © 2013 Springer International Publishing, Switzerland file_id: '18586' file_name: Riefer2013_Chapter_LithiumNiobateDielectricFuncti.pdf file_size: 517819 relation: main_file title: Lithium niobate dielectric function and second-order polarizability tensor from massively parallel ab initio calculations file_date_updated: 2020-08-30T14:57:36Z has_accepted_license: '1' isi: '1' language: - iso: eng page: 93-104 place: Cham project: - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing publication: High Performance Computing in Science and Engineering ‘13 publication_identifier: eisbn: - 978-3-319-02165-2 isbn: - 978-3-319-02164-5 publication_status: published publisher: Springer quality_controlled: '1' series_title: Transactions of the High Performance Computing Center, Stuttgart status: public title: Lithium niobate dielectric function and second-order polarizability tensor from massively parallel ab initio calculations type: book_chapter user_id: '16199' year: '2013' ... --- _id: '18476' abstract: - lang: eng text: We investigate the band dispersion and relevant electronic properties of rubrene single crystals within the GW approximation. Due to the self-energy correction, the dispersion of the highest occupied molecular orbital (HOMO) band increases by 0.10 eV compared to the dispersion of the Kohn-Sham eigenvalues within the generalized gradient approximation, and the effective hole mass consequently decreases. The resulting value of 0.90 times the electron rest mass along the Γ-Y direction in the Brillouin zone is closer to experimental measurements than that obtained from density-functional theory. The enhanced bandwidth is explained in terms of the intermolecular hybridization of the HOMO(Y) wave function along the stacking direction of the molecules. Overall, our results support the bandlike interpretation of charge-carrier transport in rubrene. article_number: '115438' article_type: original author: - first_name: Susumu full_name: Yanagisawa, Susumu last_name: Yanagisawa - first_name: Yoshitada full_name: Morikawa, Yoshitada last_name: Morikawa - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X citation: ama: 'Yanagisawa S, Morikawa Y, Schindlmayr A. HOMO band dispersion of crystalline rubrene: Effects of self-energy corrections within the GW approximation. Physical Review B. 2013;88(11). doi:10.1103/PhysRevB.88.115438' apa: 'Yanagisawa, S., Morikawa, Y., & Schindlmayr, A. (2013). HOMO band dispersion of crystalline rubrene: Effects of self-energy corrections within the GW approximation. Physical Review B, 88(11), Article 115438. https://doi.org/10.1103/PhysRevB.88.115438' bibtex: '@article{Yanagisawa_Morikawa_Schindlmayr_2013, title={HOMO band dispersion of crystalline rubrene: Effects of self-energy corrections within the GW approximation}, volume={88}, DOI={10.1103/PhysRevB.88.115438}, number={11115438}, journal={Physical Review B}, publisher={American Physical Society}, author={Yanagisawa, Susumu and Morikawa, Yoshitada and Schindlmayr, Arno}, year={2013} }' chicago: 'Yanagisawa, Susumu, Yoshitada Morikawa, and Arno Schindlmayr. “HOMO Band Dispersion of Crystalline Rubrene: Effects of Self-Energy Corrections within the GW Approximation.” Physical Review B 88, no. 11 (2013). https://doi.org/10.1103/PhysRevB.88.115438.' ieee: 'S. Yanagisawa, Y. Morikawa, and A. Schindlmayr, “HOMO band dispersion of crystalline rubrene: Effects of self-energy corrections within the GW approximation,” Physical Review B, vol. 88, no. 11, Art. no. 115438, 2013, doi: 10.1103/PhysRevB.88.115438.' mla: 'Yanagisawa, Susumu, et al. “HOMO Band Dispersion of Crystalline Rubrene: Effects of Self-Energy Corrections within the GW Approximation.” Physical Review B, vol. 88, no. 11, 115438, American Physical Society, 2013, doi:10.1103/PhysRevB.88.115438.' short: S. Yanagisawa, Y. Morikawa, A. Schindlmayr, Physical Review B 88 (2013). date_created: 2020-08-27T21:59:44Z date_updated: 2025-12-16T08:08:02Z ddc: - '530' department: - _id: '296' - _id: '35' - _id: '15' - _id: '170' - _id: '230' doi: 10.1103/PhysRevB.88.115438 external_id: isi: - '000325175600010' file: - access_level: open_access content_type: application/pdf creator: schindlm date_created: 2020-08-27T22:01:50Z date_updated: 2020-08-30T14:58:43Z description: © 2013 American Physical Society file_id: '18477' file_name: PhysRevB.88.115438.pdf file_size: 4438475 relation: main_file title: 'HOMO band dispersion of crystalline rubrene: Effects of self-energy corrections within the GW approximation' file_date_updated: 2020-08-30T14:58:43Z has_accepted_license: '1' intvolume: ' 88' isi: '1' issue: '11' language: - iso: eng oa: '1' publication: Physical Review B publication_identifier: eissn: - 1550-235X issn: - 1098-0121 publication_status: published publisher: American Physical Society quality_controlled: '1' status: public title: 'HOMO band dispersion of crystalline rubrene: Effects of self-energy corrections within the GW approximation' type: journal_article user_id: '16199' volume: 88 year: '2013' ... --- _id: '18479' abstract: - lang: eng text: The GW approximation for the electronic self-energy is an important tool for the quantitative prediction of excited states in solids, but its mathematical exploration is hampered by the fact that it must, in general, be evaluated numerically even for very simple systems. In this paper I describe a nontrivial model consisting of two electrons on the surface of a sphere, interacting with the normal long-range Coulomb potential, and show that the GW self-energy, in the absence of self-consistency, can in fact be derived completely analytically in this case. The resulting expression is subsequently used to analyze the convergence of the energy gap between the highest occupied and the lowest unoccupied quasiparticle orbital with respect to the total number of states included in the spectral summations. The asymptotic formula for the truncation error obtained in this way, whose dominant contribution is proportional to the cutoff energy to the power −3/2, may be adapted to extrapolate energy gaps in other systems. article_number: '075104' article_type: original author: - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X citation: ama: Schindlmayr A. Analytic evaluation of the electronic self-energy in the GW approximation for two electrons on a sphere. Physical Review B. 2013;87(7). doi:10.1103/PhysRevB.87.075104 apa: Schindlmayr, A. (2013). Analytic evaluation of the electronic self-energy in the GW approximation for two electrons on a sphere. Physical Review B, 87(7), Article 075104. https://doi.org/10.1103/PhysRevB.87.075104 bibtex: '@article{Schindlmayr_2013, title={Analytic evaluation of the electronic self-energy in the GW approximation for two electrons on a sphere}, volume={87}, DOI={10.1103/PhysRevB.87.075104}, number={7075104}, journal={Physical Review B}, publisher={American Physical Society}, author={Schindlmayr, Arno}, year={2013} }' chicago: Schindlmayr, Arno. “Analytic Evaluation of the Electronic Self-Energy in the GW Approximation for Two Electrons on a Sphere.” Physical Review B 87, no. 7 (2013). https://doi.org/10.1103/PhysRevB.87.075104. ieee: 'A. Schindlmayr, “Analytic evaluation of the electronic self-energy in the GW approximation for two electrons on a sphere,” Physical Review B, vol. 87, no. 7, Art. no. 075104, 2013, doi: 10.1103/PhysRevB.87.075104.' mla: Schindlmayr, Arno. “Analytic Evaluation of the Electronic Self-Energy in the GW Approximation for Two Electrons on a Sphere.” Physical Review B, vol. 87, no. 7, 075104, American Physical Society, 2013, doi:10.1103/PhysRevB.87.075104. short: A. Schindlmayr, Physical Review B 87 (2013). date_created: 2020-08-27T22:09:04Z date_updated: 2025-12-16T11:08:31Z ddc: - '530' department: - _id: '296' - _id: '35' - _id: '15' - _id: '170' - _id: '230' doi: 10.1103/PhysRevB.87.075104 external_id: arxiv: - '1302.6368' isi: - '000314682500002' file: - access_level: open_access content_type: application/pdf creator: schindlm date_created: 2020-08-28T10:01:56Z date_updated: 2020-08-30T14:54:49Z description: © 2013 American Physical Society file_id: '18541' file_name: PhysRevB.87.075104.pdf file_size: 229196 relation: main_file title: Analytic evaluation of the electronic self-energy in the GW approximation for two electrons on a sphere file_date_updated: 2020-08-30T14:54:49Z has_accepted_license: '1' intvolume: ' 87' isi: '1' issue: '7' language: - iso: eng oa: '1' publication: Physical Review B publication_identifier: eissn: - 1550-235X issn: - 1098-0121 publication_status: published publisher: American Physical Society quality_controlled: '1' status: public title: Analytic evaluation of the electronic self-energy in the GW approximation for two electrons on a sphere type: journal_article user_id: '16199' volume: 87 year: '2013' ... --- _id: '18542' abstract: - lang: eng text: 'We present recent advances in numerical implementations of hybrid functionals and the GW approximation within the full-potential linearized augmented-plane-wave (FLAPW) method. The former is an approximation for the exchange–correlation contribution to the total energy functional in density-functional theory, and the latter is an approximation for the electronic self-energy in the framework of many-body perturbation theory. All implementations employ the mixed product basis, which has evolved into a versatile basis for the products of wave functions, describing the incoming and outgoing states of an electron that is scattered by interacting with another electron. It can thus be used for representing the nonlocal potential in hybrid functionals as well as the screened interaction and related quantities in GW calculations. In particular, the six-dimensional space integrals of the Hamiltonian exchange matrix elements (and exchange self-energy) decompose into sums over vector–matrix–vector products, which can be evaluated easily. The correlation part of the GW self-energy, which contains a time or frequency dependence, is calculated on the imaginary frequency axis with a subsequent analytic continuation to the real axis or, alternatively, by a direct frequency convolution of the Green function G and the dynamically screened Coulomb interaction W along a contour integration path that avoids the poles of the Green function. Hybrid-functional and GW calculations are notoriously computationally expensive. We present a number of tricks that reduce the computational cost considerably, including the use of spatial and time-reversal symmetries, modifications of the mixed product basis with the aim to optimize it for the correlation self-energy and another modification that makes the Coulomb matrix sparse, analytic expansions of the interaction potentials around the point of divergence at k=0, and a nested density and density-matrix convergence scheme for hybrid-functional calculations. We show CPU timings for prototype semiconductors and illustrative results for GdN and ZnO. ' article_number: '293201' article_type: review author: - first_name: Christoph full_name: Friedrich, Christoph last_name: Friedrich - first_name: Markus full_name: Betzinger, Markus last_name: Betzinger - first_name: Martin full_name: Schlipf, Martin last_name: Schlipf - first_name: Stefan full_name: Blügel, Stefan last_name: Blügel - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X citation: ama: 'Friedrich C, Betzinger M, Schlipf M, Blügel S, Schindlmayr A. Hybrid functionals and GW approximation in the FLAPW method. Journal of Physics: Condensed Matter. 2012;24(29). doi:10.1088/0953-8984/24/29/293201' apa: 'Friedrich, C., Betzinger, M., Schlipf, M., Blügel, S., & Schindlmayr, A. (2012). Hybrid functionals and GW approximation in the FLAPW method. Journal of Physics: Condensed Matter, 24(29), Article 293201. https://doi.org/10.1088/0953-8984/24/29/293201' bibtex: '@article{Friedrich_Betzinger_Schlipf_Blügel_Schindlmayr_2012, title={Hybrid functionals and GW approximation in the FLAPW method}, volume={24}, DOI={10.1088/0953-8984/24/29/293201}, number={29293201}, journal={Journal of Physics: Condensed Matter}, publisher={IOP Publishing}, author={Friedrich, Christoph and Betzinger, Markus and Schlipf, Martin and Blügel, Stefan and Schindlmayr, Arno}, year={2012} }' chicago: 'Friedrich, Christoph, Markus Betzinger, Martin Schlipf, Stefan Blügel, and Arno Schindlmayr. “Hybrid Functionals and GW Approximation in the FLAPW Method.” Journal of Physics: Condensed Matter 24, no. 29 (2012). https://doi.org/10.1088/0953-8984/24/29/293201.' ieee: 'C. Friedrich, M. Betzinger, M. Schlipf, S. Blügel, and A. Schindlmayr, “Hybrid functionals and GW approximation in the FLAPW method,” Journal of Physics: Condensed Matter, vol. 24, no. 29, Art. no. 293201, 2012, doi: 10.1088/0953-8984/24/29/293201.' mla: 'Friedrich, Christoph, et al. “Hybrid Functionals and GW Approximation in the FLAPW Method.” Journal of Physics: Condensed Matter, vol. 24, no. 29, 293201, IOP Publishing, 2012, doi:10.1088/0953-8984/24/29/293201.' short: 'C. Friedrich, M. Betzinger, M. Schlipf, S. Blügel, A. Schindlmayr, Journal of Physics: Condensed Matter 24 (2012).' date_created: 2020-08-28T10:14:44Z date_updated: 2025-12-16T08:09:33Z ddc: - '530' department: - _id: '296' - _id: '35' - _id: '15' - _id: '170' - _id: '230' doi: 10.1088/0953-8984/24/29/293201 external_id: isi: - '000306270700001' pmid: - '22773268' file: - access_level: closed content_type: application/pdf creator: schindlm date_created: 2020-08-28T14:30:29Z date_updated: 2020-08-30T15:00:14Z description: © 2012 IOP Publishing Ltd file_id: '18580' file_name: Friedrich_2012_J._Phys. _Condens._Matter_24_293201.pdf file_size: 1059896 relation: main_file title: Hybrid functionals and GW approximation in the FLAPW method file_date_updated: 2020-08-30T15:00:14Z has_accepted_license: '1' intvolume: ' 24' isi: '1' issue: '29' language: - iso: eng pmid: '1' publication: 'Journal of Physics: Condensed Matter' publication_identifier: eissn: - 1361-648X issn: - 0953-8984 publication_status: published publisher: IOP Publishing quality_controlled: '1' status: public title: Hybrid functionals and GW approximation in the FLAPW method type: journal_article user_id: '16199' volume: 24 year: '2012' ... --- _id: '4048' abstract: - lang: eng text: We present an ab-initio method for calculating nonlinear and nonlocal optical effects in metallic slabs with sub-wavelength thickness. We find a strong localization of the second-harmonic current at the metal-vacuum interface. article_number: JTuI59 author: - first_name: Mathias full_name: Wand, Mathias last_name: Wand - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X - first_name: Torsten full_name: Meier, Torsten id: '344' last_name: Meier orcid: 0000-0001-8864-2072 - first_name: Jens full_name: Förstner, Jens id: '158' last_name: Förstner orcid: 0000-0001-7059-9862 citation: ama: "Wand M, Schindlmayr A, Meier T, Förstner J. Theoretical approach to the ultrafast nonlinear optical response of metal slabs. In: CLEO:2011 - Laser Applications to Photonic Applications\t. OSA Technical Digest. Optical Society of America; 2011. doi:10.1364/CLEO_AT.2011.JTuI59" apa: "Wand, M., Schindlmayr, A., Meier, T., & Förstner, J. (2011). Theoretical approach to the ultrafast nonlinear optical response of metal slabs. CLEO:2011 - Laser Applications to Photonic Applications\t, Article JTuI59. Conference on Lasers and Electro-Optics 2011, Baltimore, Maryland, United States. https://doi.org/10.1364/CLEO_AT.2011.JTuI59" bibtex: "@inproceedings{Wand_Schindlmayr_Meier_Förstner_2011, series={OSA Technical Digest}, title={Theoretical approach to the ultrafast nonlinear optical response of metal slabs}, DOI={10.1364/CLEO_AT.2011.JTuI59}, number={JTuI59}, booktitle={CLEO:2011 - Laser Applications to Photonic Applications\t}, publisher={Optical Society of America}, author={Wand, Mathias and Schindlmayr, Arno and Meier, Torsten and Förstner, Jens}, year={2011}, collection={OSA Technical Digest} }" chicago: "Wand, Mathias, Arno Schindlmayr, Torsten Meier, and Jens Förstner. “Theoretical Approach to the Ultrafast Nonlinear Optical Response of Metal Slabs.” In CLEO:2011 - Laser Applications to Photonic Applications\t. OSA Technical Digest. Optical Society of America, 2011. https://doi.org/10.1364/CLEO_AT.2011.JTuI59." ieee: 'M. Wand, A. Schindlmayr, T. Meier, and J. Förstner, “Theoretical approach to the ultrafast nonlinear optical response of metal slabs,” presented at the Conference on Lasers and Electro-Optics 2011, Baltimore, Maryland, United States, 2011, doi: 10.1364/CLEO_AT.2011.JTuI59.' mla: "Wand, Mathias, et al. “Theoretical Approach to the Ultrafast Nonlinear Optical Response of Metal Slabs.” CLEO:2011 - Laser Applications to Photonic Applications\t, JTuI59, Optical Society of America, 2011, doi:10.1364/CLEO_AT.2011.JTuI59." short: "M. Wand, A. Schindlmayr, T. Meier, J. Förstner, in: CLEO:2011 - Laser Applications to Photonic Applications\t, Optical Society of America, 2011." conference: end_date: 2011-05-06 location: Baltimore, Maryland, United States name: Conference on Lasers and Electro-Optics 2011 start_date: 2011-05-01 date_created: 2018-08-22T10:35:41Z date_updated: 2023-04-20T14:55:23Z ddc: - '530' department: - _id: '293' - _id: '296' - _id: '230' - _id: '15' - _id: '170' - _id: '35' doi: 10.1364/CLEO_AT.2011.JTuI59 external_id: isi: - '000295612403066' file: - access_level: closed content_type: application/pdf creator: schindlm date_created: 2020-08-28T15:51:37Z date_updated: 2020-08-30T15:02:29Z description: © 2011 Optical Society of America file_id: '18587' file_name: 05951090.pdf file_size: 135730 relation: main_file title: Theoretical approach to the ultrafast nonlinear optical response of metal slabs file_date_updated: 2020-08-30T15:02:29Z has_accepted_license: '1' isi: '1' keyword: - tet_topic_shg language: - iso: eng publication: "CLEO:2011 - Laser Applications to Photonic Applications\t" publication_identifier: eisbn: - 978-1-55752-911-4 isbn: - 978-1-4577-1223-4 issn: - 2160-8989 publication_status: published publisher: Optical Society of America series_title: OSA Technical Digest status: public title: Theoretical approach to the ultrafast nonlinear optical response of metal slabs type: conference user_id: '16199' year: '2011' ... --- _id: '4091' abstract: - lang: eng text: 'We present a nonequilibrium ab initio method for calculating nonlinear and nonlocal optical effects in metallic slabs with a thickness of several nanometers. The numerical analysis is based on the full solution of the time‐dependent Kohn–Sham equations for a jellium system and allows to study the optical response of metal electrons subject to arbitrarily shaped intense light pulses. We find a strong localization of the generated second‐harmonic current in the surface regions of the slabs. ' article_type: original author: - first_name: Mathias full_name: Wand, Mathias last_name: Wand - first_name: Arno full_name: Schindlmayr, Arno id: '458' last_name: Schindlmayr orcid: 0000-0002-4855-071X - first_name: Torsten full_name: Meier, Torsten id: '344' last_name: Meier orcid: 0000-0001-8864-2072 - first_name: Jens full_name: Förstner, Jens id: '158' last_name: Förstner orcid: 0000-0001-7059-9862 citation: ama: Wand M, Schindlmayr A, Meier T, Förstner J. Simulation of the ultrafast nonlinear optical response of metal slabs. Physica Status Solidi B. 2011;248(4):887-891. doi:10.1002/pssb.201001219 apa: Wand, M., Schindlmayr, A., Meier, T., & Förstner, J. (2011). Simulation of the ultrafast nonlinear optical response of metal slabs. Physica Status Solidi B, 248(4), 887–891. https://doi.org/10.1002/pssb.201001219 bibtex: '@article{Wand_Schindlmayr_Meier_Förstner_2011, title={Simulation of the ultrafast nonlinear optical response of metal slabs}, volume={248}, DOI={10.1002/pssb.201001219}, number={4}, journal={Physica Status Solidi B}, publisher={Wiley-VCH}, author={Wand, Mathias and Schindlmayr, Arno and Meier, Torsten and Förstner, Jens}, year={2011}, pages={887–891} }' chicago: 'Wand, Mathias, Arno Schindlmayr, Torsten Meier, and Jens Förstner. “Simulation of the Ultrafast Nonlinear Optical Response of Metal Slabs.” Physica Status Solidi B 248, no. 4 (2011): 887–91. https://doi.org/10.1002/pssb.201001219.' ieee: 'M. Wand, A. Schindlmayr, T. Meier, and J. Förstner, “Simulation of the ultrafast nonlinear optical response of metal slabs,” Physica Status Solidi B, vol. 248, no. 4, pp. 887–891, 2011, doi: 10.1002/pssb.201001219.' mla: Wand, Mathias, et al. “Simulation of the Ultrafast Nonlinear Optical Response of Metal Slabs.” Physica Status Solidi B, vol. 248, no. 4, Wiley-VCH, 2011, pp. 887–91, doi:10.1002/pssb.201001219. short: M. Wand, A. Schindlmayr, T. Meier, J. Förstner, Physica Status Solidi B 248 (2011) 887–891. date_created: 2018-08-23T09:53:38Z date_updated: 2025-12-16T11:26:04Z ddc: - '530' department: - _id: '293' - _id: '230' - _id: '296' - _id: '15' - _id: '170' - _id: '35' - _id: '34' - _id: '61' doi: 10.1002/pssb.201001219 external_id: isi: - '000288856300020' file: - access_level: closed content_type: application/pdf creator: hclaudia date_created: 2018-08-23T09:55:13Z date_updated: 2020-08-30T15:01:30Z description: © 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim file_id: '4092' file_name: 2011 Wand,Schindlmayr,Meier,Förstner_Simulation of the ultrafast nonlinear optical response of metal slabs.pdf file_size: 739579 relation: main_file title: Simulation of the ultrafast optical response of metal slabs file_date_updated: 2020-08-30T15:01:30Z has_accepted_license: '1' intvolume: ' 248' isi: '1' issue: '4' keyword: - tet_topic_shg language: - iso: eng page: 887-891 publication: Physica Status Solidi B publication_identifier: eissn: - 1521-3951 issn: - 0370-1972 publication_status: published publisher: Wiley-VCH quality_controlled: '1' status: public title: Simulation of the ultrafast nonlinear optical response of metal slabs type: journal_article user_id: '16199' volume: 248 year: '2011' ...