@article{13241, abstract = {{The accuracy of water models derived from ab initio molecular dynamics simulations by means on an improved force-matching scheme is assessed for various thermodynamic, transport, and structural properties. It is found that although the resulting force-matched water models are typically less accurate than fully empirical force fields in predicting thermodynamic properties, they are nevertheless much more accurate than generally appreciated in reproducing the structure of liquid water and in fact superseding most of the commonly used empirical water models. This development demonstrates the feasibility to routinely parametrize computationally efficient yet predictive potential energy functions based on accurate ab initio molecular dynamics simulations for a large variety of different systems. © 2016 Wiley Periodicals, Inc.}}, author = {{Köster, Andreas and Spura, Thomas and Rutkai, Gábor and Kessler, Jan and Wiebeler, Hendrik and Vrabec, Jadran and Kühne, Thomas D.}}, journal = {{Journal of Computational Chemistry}}, keywords = {{liquid water, force matching, ab initio, molecular dynamics, Monte Carlo}}, number = {{19}}, pages = {{1828--1838}}, title = {{{Assessing the accuracy of improved force-matched water models derived from Ab initio molecular dynamics simulations}}}, doi = {{10.1002/jcc.24398}}, volume = {{37}}, year = {{2016}}, } @article{13252, author = {{Tierney, Kevin and Pacino, Dario and Voß, Stefan}}, issn = {{1936-6582}}, journal = {{Flexible Services and Manufacturing Journal}}, pages = {{223--259}}, title = {{{Solving the Pre-Marshalling Problem to Optimality with A* and IDA*}}}, doi = {{10.1007/s10696-016-9246-6}}, year = {{2016}}, } @article{10026, abstract = {{Congruent lithium niobate and lithium tantalate mixed crystals have been grown over the complete compositional range with the Czochralski method. The structural and vibrational properties of the mixed crystals are studied extensively by x-ray diffraction measurements, Raman spectroscopy, and density functional theory. The measured lattice parameters and vibrational frequencies are in good agreement with our theoretical predictions. The observed dependence of the Raman frequencies on the crystal composition is discussed on the basis of the calculated phonon displacement patterns. The phononic contribution to the static dielectric tensor is calculated by means of the generalized Lyddane-Sachs-Teller relation. Due to the pronounced dependence of the optical response on the Ta concentration, lithium niobate tantalate mixed crystals represent a perfect model system to study the properties of uniaxial mixed ferroelectric materials for application in integrated optics.}}, author = {{Rüsing, Michael and Sanna, Simone and Neufeld, Sergej and Berth, Gerhard and Schmidt, Wolf Gero and Zrenner, Artur and Yu, H. and Wang, Y. and Zhang, H.}}, issn = {{2469-9950}}, journal = {{Physical Review B}}, title = {{{Vibrational properties of LiNb1−xTaxO3 mixed crystals}}}, doi = {{10.1103/physrevb.93.184305}}, year = {{2016}}, } @article{6555, author = {{Claes, Leander and Meyer, Thorsten and Bause, Fabian and Rautenberg, Jens and Henning, Bernd}}, issn = {{2194-878X}}, journal = {{Journal of Sensors and Sensor Systems}}, number = {{1}}, pages = {{187--196}}, title = {{{Determination of the material properties of polymers using laser-generated broadband ultrasound}}}, doi = {{10.5194/jsss-5-187-2016}}, volume = {{5}}, year = {{2016}}, } @article{13917, abstract = {{We present the synthesis of indium oxide (In2O3) inverse opal films with photonic stop bands in the visible range by a structure replication method. Artificial opal films made of poly(methyl methacrylate) (PMMA) spheres are utilized as template. The opal films are deposited via sedimentation facilitated by ultrasonication, and then impregnated by indium nitrate solution, which is thermally converted to In2O3 after drying. The quality of the resulting inverse opal film depends on many parameters; in this study the water content of the indium nitrate/PMMA composite after drying is investigated. Comparison of the reflectance spectra recorded by vis-spectroscopy with simulated data shows a good agreement between the peak position and calculated stop band positions for the inverse opals. This synthesis is less complex and highly efficient compared to most other techniques and is suitable for use in many applications.}}, author = {{Amrehn, Sabrina and Berghoff, Daniel and Nikitin, Andreas and Reichelt, Matthias and Wu, Xia and Meier, Torsten and Wagner, Thorsten}}, issn = {{1569-4410}}, journal = {{Photonics and Nanostructures - Fundamentals and Applications}}, pages = {{55--63}}, title = {{{Indium oxide inverse opal films synthesized by structure replication method}}}, doi = {{10.1016/j.photonics.2016.02.005}}, volume = {{19}}, year = {{2016}}, } @inproceedings{13918, author = {{Podzimski, Reinold and Duc, Huynh Thanh and Priyadarshi, Shekhar and Schmidt, Christian and Bieler, Mark and Meier, Torsten}}, booktitle = {{Ultrafast Phenomena and Nanophotonics XX}}, editor = {{Betz, Markus and Elezzabi, Abdulhakem Y.}}, publisher = {{SPIE}}, title = {{{Photocurrents in semiconductors and semiconductor quantum wells analyzed by k.p-based Bloch equations}}}, doi = {{10.1117/12.2208572}}, volume = {{9746}}, year = {{2016}}, } @article{22942, abstract = {{A microscopic approach that is based on the multisubband semiconductor Bloch equations formulated in the basis of a 14-band k⋅p model is employed to compute the temporal dynamics of photocurrents in GaAs quantum wells following excitation with femtosecond laser pulses. This approach provides a transparent description of the interband, intersubband, and intraband excitations, fully includes all resonant as well as off-resonant excitations, and treats the light-matter interaction nonperturbatively. For linearly polarized excitations, the photocurrents contain contributions from shift and rectification currents. We numerically compute and analyze these currents generated by excitation with femtosecond laser pulses for [110]- and [111]-oriented GaAs quantum wells. It is shown that the often employed perturbative χ(2) approach breaks down for peak fields larger than about 10 kV/cm, and that nonperturbative effects lead to a reduction of the peak values of the shift and rectification currents and to temporal oscillations that originate from Rabi flopping. In particular, we find a complex oscillatory photon energy dependence of the magnitudes of the shift and rectification currents. Our simulations demonstrate that this dependence is the result of mixing between the heavy- and light-hole valence bands. This is a surprising finding since the band mixing has an even larger influence on the strength of the photocurrents than the absorption coefficient. For [110]-oriented GaAs quantum wells, the calculated photon energy dependence is compared to experimental results, and good agreement is obtained. This validates our theoretical approach.}}, author = {{Duc, Huynh Thanh and Podzimski, Reinold and Priyadarshi, Shekhar and Bieler, Mark and Meier, Torsten}}, issn = {{2469-9950}}, journal = {{Physical Review B}}, number = {{8}}, publisher = {{American Physical Society}}, title = {{{Ultrafast shift and rectification photocurrents in GaAs quantum wells: Excitation intensity dependence and the importance of band mixing}}}, doi = {{10.1103/physrevb.94.085305}}, volume = {{94}}, year = {{2016}}, } @article{13920, abstract = {{We investigate the transient optical response in high-quality Cd0.88Zn0.12Te crystals in the regime of slow light propagation on the lower exciton-polariton branch. Femtosecond photoexcitation leads to very substantial transmission changes in a ∼10-meV broad spectral range within the transparency window of the unexcited semiconductor. These nonlinear optical signatures decay on picosecond time scales governed by carrier thermalization and recombination. The temporal and spectral dependence indicate the dynamical optical response as arising from excitation-induced dephasing and perturbed free induction decay. Model simulations for the optical response taking into account the actual exciton-polariton dispersion and excitation-induced dephasing of a nonlinearly driven two-level system support this interpretation.}}, author = {{Lohrenz, J. and Melzer, S. and Ruppert, C. and Akimov, I. A. and Mariette, H. and Reichelt, Matthias and Trautmann, Alexander and Meier, Torsten and Betz, M.}}, issn = {{2469-9950}}, journal = {{Physical Review B}}, number = {{7}}, title = {{{Ultrafast dynamical response of the lower exciton-polariton branch in CdZnTe}}}, doi = {{10.1103/physrevb.93.075201}}, volume = {{93}}, year = {{2016}}, } @inproceedings{25, author = {{Lass, Michael and Kühne, Thomas and Plessl, Christian}}, booktitle = {{Workshop on Approximate Computing (AC)}}, title = {{{Using Approximate Computing in Scientific Codes}}}, year = {{2016}}, } @article{10024, abstract = {{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.}}, author = {{Riefer, Arthur and Friedrich, Michael and Sanna, Simone and Gerstmann, Uwe and Schindlmayr, Arno and Schmidt, Wolf Gero}}, issn = {{2469-9969}}, journal = {{Physical Review B}}, number = {{7}}, publisher = {{American Physical Society}}, title = {{{LiNbO3 electronic structure: Many-body interactions, spin-orbit coupling, and thermal effects}}}, doi = {{10.1103/PhysRevB.93.075205}}, volume = {{93}}, year = {{2016}}, } @article{10025, abstract = {{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.}}, author = {{Friedrich, Michael and Schindlmayr, Arno and Schmidt, Wolf Gero and Sanna, Simone}}, issn = {{1521-3951}}, journal = {{Physica Status Solidi B}}, number = {{4}}, pages = {{683--689}}, publisher = {{Wiley-VCH}}, title = {{{LiTaO3 phonon dispersion and ferroelectric transition calculated from first principles}}}, doi = {{10.1002/pssb.201552576}}, volume = {{253}}, year = {{2016}}, } @article{13492, author = {{Tebi, Stefano and Aldahhak, Hazem and Serrano, Giulia and Schöfberger, Wolfgang and Rauls, Eva and Schmidt, Wolf Gero and Koch, Reinhold and Müllegger, Stefan}}, issn = {{0957-4484}}, journal = {{Nanotechnology}}, title = {{{Manipulation resolves non-trivial structure of corrole monolayer on Ag(111)}}}, doi = {{10.1088/0957-4484/27/2/025704}}, volume = {{27}}, year = {{2016}}, } @article{13476, author = {{Vollmers, Nora Jenny and Müller, Patrick and Hoffmann, Alexander and Herres-Pawlis, Sonja and Rohrmüller, Martin and Schmidt, Wolf Gero and Gerstmann, Uwe and Bauer, Matthias}}, issn = {{0020-1669}}, journal = {{Inorganic Chemistry}}, pages = {{11694--11706}}, title = {{{Experimental and Theoretical High-Energy-Resolution X-ray Absorption Spectroscopy: Implications for the Investigation of the Entatic State}}}, doi = {{10.1021/acs.inorgchem.6b01704}}, volume = {{55}}, year = {{2016}}, } @article{13477, author = {{Witte, Matthias and Grimm-Lebsanft, Benjamin and Goos, Arne and Binder, Stephan and Rübhausen, Michael and Bernard, Martin and Neuba, Adam and Gorelsky, Serge and Gerstmann, Uwe and Henkel, Gerald and Schmidt, Wolf Gero and Herres-Pawlis, Sonja}}, issn = {{0192-8651}}, journal = {{Journal of Computational Chemistry}}, number = {{23-24}}, pages = {{2181--2192}}, title = {{{Optical response of the Cu2S2diamond core in Cu2II(NGuaS)2Cl2}}}, doi = {{10.1002/jcc.24439}}, volume = {{37}}, year = {{2016}}, } @article{13479, author = {{Lücke, Andreas and Ortmann, Frank and Panhans, Michel and Sanna, Simone and Rauls, Eva and Gerstmann, Uwe and Schmidt, Wolf Gero}}, issn = {{1520-6106}}, journal = {{The Journal of Physical Chemistry B}}, pages = {{5572--5580}}, title = {{{Temperature-Dependent Hole Mobility and Its Limit in Crystal-Phase P3HT Calculated from First Principles}}}, doi = {{10.1021/acs.jpcb.6b03598}}, volume = {{120}}, year = {{2016}}, } @article{13480, author = {{Paulheim, A. and Marquardt, C. and Aldahhak, Hazem and Rauls, E. and Schmidt, Wolf Gero and Sokolowski, M.}}, issn = {{1932-7447}}, journal = {{The Journal of Physical Chemistry C}}, pages = {{11926--11937}}, title = {{{Inhomogeneous and Homogeneous Line Broadening of Optical Spectra of PTCDA Molecules Adsorbed at Step Edges of Alkali Halide Surfaces}}}, doi = {{10.1021/acs.jpcc.6b01956}}, volume = {{10}}, year = {{2016}}, } @article{13485, author = {{Sanna, S. and Dues, C. and Schmidt, Wolf Gero and Timmer, F. and Wollschläger, J. and Franz, M. and Appelfeller, S. and Dähne, M.}}, issn = {{2469-9950}}, journal = {{Physical Review B}}, number = {{19}}, title = {{{Rare-earth silicide thin films on the Si(111) surface}}}, doi = {{10.1103/physrevb.93.195407}}, volume = {{93}}, year = {{2016}}, } @article{13487, author = {{Witte, M. and Gerstmann, Uwe and Neuba, Adam and Henkel, G. and Schmidt, Wolf Gero}}, issn = {{0192-8651}}, journal = {{Journal of Computational Chemistry}}, pages = {{1005--1018}}, title = {{{Density functional theory of the CuA-like Cu2S2 diamond core in Cu 2II(NGuaS)2Cl2}}}, doi = {{10.1002/jcc.24289}}, volume = {{37}}, year = {{2016}}, } @article{13481, author = {{Jeckelmann, Eric and Sanna, Simone and Schmidt, Wolf Gero and Speiser, Eugen and Esser, Norbert}}, issn = {{2469-9950}}, journal = {{Physical Review B}}, number = {{24}}, title = {{{Grand canonical Peierls transition in In/Si(111)}}}, doi = {{10.1103/physrevb.93.241407}}, volume = {{93}}, year = {{2016}}, } @article{13478, author = {{Speiser, E. and Esser, N. and Wippermann, S. and Schmidt, Wolf Gero}}, issn = {{2469-9950}}, journal = {{Physical Review B}}, number = {{7}}, title = {{{Surface vibrational Raman modes of In:Si(111)(4×1)and(8×2)nanowires}}}, doi = {{10.1103/physrevb.94.075417}}, volume = {{94}}, year = {{2016}}, }