EPR spectroscopy reveals the universality class and dynamic effects of the [NH4][Zn(HCOO)3] hybrid formate framework.
}}, author = {{Navickas, Marius and Giriūnas, Laisvydas and Kalendra, Vidmantas and Biktagirov, Timur and Gerstmann, Uwe and Schmidt, Wolf Gero and Mączka, Mirosław and Pöppl, Andreas and Banys, Jūras and Šimėnas, Mantas}}, issn = {{1463-9076}}, journal = {{Physical Chemistry Chemical Physics}}, pages = {{8513--8521}}, title = {{{Electron paramagnetic resonance study of ferroelectric phase transition and dynamic effects in a Mn2+ doped [NH4][Zn(HCOO)3] hybrid formate framework}}}, doi = {{10.1039/d0cp01612h}}, volume = {{22}}, year = {{2020}}, } @article{29745, author = {{Biktagirov, Timur and Gerstmann, Uwe}}, issn = {{2643-1564}}, journal = {{Physical Review Research}}, keywords = {{General Engineering}}, number = {{2}}, publisher = {{American Physical Society (APS)}}, title = {{{Spin-orbit driven electrical manipulation of the zero-field splitting in high-spin centers in solids}}}, doi = {{10.1103/physrevresearch.2.023071}}, volume = {{2}}, year = {{2020}}, } @article{19189, abstract = {{Density-functional theory calculations of (TiO2)n clusters (n = 1–5) in the gas phase and adsorbed on pristine graphene as well as graphene quantum dots are presented. The cluster adsorption is found to be dominated by van der Waals forces. The electronic structure and in particular the excitation energies of the bare clusters and the TiO2/graphene composites are found to vary largely in dependence on the size of the respective constituents. This holds in particular for the energy and the spatial localization of the highest occupied and lowest unoccupied molecular orbitals. In addition to a substantial gap narrowing, a pronounced separation of photoexcited electrons and holes is predicted in some instances. This is expected to prolong the lifetime of photoexcited carriers. Altogether, TiO2/graphene composites are predicted to be promising photocatalysts with improved electronic and photocatalytic properties compared to bulk TiO2.}}, author = {{Badalov, Sabuhi and Wilhelm, René and Schmidt, Wolf Gero}}, issn = {{0192-8651}}, journal = {{Journal of Computational Chemistry}}, pages = {{1921--1930}}, publisher = {{Willey}}, title = {{{Photocatalytic properties of graphene‐supported titania clusters from density‐functional theory}}}, doi = {{10.1002/jcc.26363}}, year = {{2020}}, } @inproceedings{20770, author = {{Hannes, Wolf-Rüdiger and Meier, Torsten}}, booktitle = {{Ultrafast Phenomena and Nanophotonics XXIV}}, editor = {{Betz, Markus and Elezzabi, Abdulhakem Y.}}, isbn = {{9781510633193}}, pages = {{112780S}}, title = {{{k.p-based multiband simulations of non-degenerate two-photon absorption in bulk GaAs}}}, doi = {{10.1117/12.2545924}}, volume = {{11278}}, year = {{2020}}, } @article{20682, author = {{Bocchini, Adriana and Eigner, Christof and Silberhorn, Christine and Schmidt, Wolf Gero and Gerstmann, Uwe}}, journal = {{Phys. Rev. Materials}}, pages = {{124402}}, publisher = {{American Physical Society}}, title = {{{Understanding gray track formation in KTP: Ti^3+ centers studied from first principles}}}, doi = {{10.1103/PhysRevMaterials.4.124402}}, volume = {{4}}, year = {{2020}}, } @article{22266, author = {{Grabo, Matti and Staggenborg, Christoph and Philippi, Kai Alexander and Kenig, Eugeny}}, issn = {{2296-598X}}, journal = {{Frontiers in Energy Research}}, title = {{{Modeling and Optimization of Rectangular Latent Heat Storage Elements in an Air-Guided Heat Storage System}}}, doi = {{10.3389/fenrg.2020.571787}}, volume = {{8}}, year = {{2020}}, } @article{15945, author = {{Tinkloh, Steffen Rainer and Wu, Tao and Tröster, Thomas and Niendorf, Thomas}}, issn = {{0263-8223}}, journal = {{Composite Structures}}, title = {{{A micromechanical-based finite element simulation of process-induced residual stresses in metal-CFRP-hybrid structures}}}, doi = {{10.1016/j.compstruct.2020.111926}}, volume = {{238}}, year = {{2020}}, } @inproceedings{23409, author = {{Bertling, René and Hack, Mathias and Ausner, Ilja and Kenig, Eugeny}}, title = {{{CFD Simulation of Film and Rivulet Flows on Microstructured Surfaces}}}, year = {{2020}}, } @article{16277, abstract = {{CP2K is an open source electronic structure and molecular dynamics software package to perform atomistic simulations of solid-state, liquid, molecular, and biological systems. It is especially aimed at massively parallel and linear-scaling electronic structure methods and state-of-theart ab initio molecular dynamics simulations. Excellent performance for electronic structure calculations is achieved using novel algorithms implemented for modern high-performance computing systems. This review revisits the main capabilities of CP2K to perform efficient and accurate electronic structure simulations. The emphasis is put on density functional theory and multiple post–Hartree–Fock methods using the Gaussian and plane wave approach and its augmented all-electron extension.}}, author = {{Kühne, Thomas and Iannuzzi, Marcella and Ben, Mauro Del and Rybkin, Vladimir V. and Seewald, Patrick and Stein, Frederick and Laino, Teodoro and Khaliullin, Rustam Z. and Schütt, Ole and Schiffmann, Florian and Golze, Dorothea and Wilhelm, Jan and Chulkov, Sergey and Mohammad Hossein Bani-Hashemian, Mohammad Hossein Bani-Hashemian and Weber, Valéry and Borstnik, Urban and Taillefumier, Mathieu and Jakobovits, Alice Shoshana and Lazzaro, Alfio and Pabst, Hans and Müller, Tiziano and Schade, Robert and Guidon, Manuel and Andermatt, Samuel and Holmberg, Nico and Schenter, Gregory K. and Hehn, Anna and Bussy, Augustin and Belleflamme, Fabian and Tabacchi, Gloria and Glöß, Andreas and Lass, Michael and Bethune, Iain and Mundy, Christopher J. and Plessl, Christian and Watkins, Matt and VandeVondele, Joost and Krack, Matthias and Hutter, Jürg}}, journal = {{The Journal of Chemical Physics}}, number = {{19}}, title = {{{CP2K: An electronic structure and molecular dynamics software package - Quickstep: Efficient and accurate electronic structure calculations}}}, doi = {{10.1063/5.0007045}}, volume = {{152}}, year = {{2020}}, } @inproceedings{16898, abstract = {{Electronic structure calculations based on density-functional theory (DFT) represent a significant part of today's HPC workloads and pose high demands on high-performance computing resources. To perform these quantum-mechanical DFT calculations on complex large-scale systems, so-called linear scaling methods instead of conventional cubic scaling methods are required. In this work, we take up the idea of the submatrix method and apply it to the DFT computations in the software package CP2K. For that purpose, we transform the underlying numeric operations on distributed, large, sparse matrices into computations on local, much smaller and nearly dense matrices. This allows us to exploit the full floating-point performance of modern CPUs and to make use of dedicated accelerator hardware, where performance has been limited by memory bandwidth before. We demonstrate both functionality and performance of our implementation and show how it can be accelerated with GPUs and FPGAs.}}, author = {{Lass, Michael and Schade, Robert and Kühne, Thomas and Plessl, Christian}}, booktitle = {{Proc. International Conference for High Performance Computing, Networking, Storage and Analysis (SC)}}, location = {{Atlanta, GA, US}}, pages = {{1127--1140}}, publisher = {{IEEE Computer Society}}, title = {{{A Submatrix-Based Method for Approximate Matrix Function Evaluation in the Quantum Chemistry Code CP2K}}}, doi = {{10.1109/SC41405.2020.00084}}, year = {{2020}}, } @inproceedings{21632, abstract = {{FPGAs have found increasing adoption in data center applications since a new generation of high-level tools have become available which noticeably reduce development time for FPGA accelerators and still provide high-quality results. There is, however, no high-level benchmark suite available, which specifically enables a comparison of FPGA architectures, programming tools, and libraries for HPC applications. To fill this gap, we have developed an OpenCL-based open-source implementation of the HPCC benchmark suite for Xilinx and Intel FPGAs. This benchmark can serve to analyze the current capabilities of FPGA devices, cards, and development tool flows, track progress over time, and point out specific difficulties for FPGA acceleration in the HPC domain. Additionally, the benchmark documents proven performance optimization patterns. We will continue optimizing and porting the benchmark for new generations of FPGAs and design tools and encourage active participation to create a valuable tool for the community. To fill this gap, we have developed an OpenCL-based open-source implementation of the HPCC benchmark suite for Xilinx and Intel FPGAs. This benchmark can serve to analyze the current capabilities of FPGA devices, cards, and development tool flows, track progress over time, and point out specific difficulties for FPGA acceleration in the HPC domain. Additionally, the benchmark documents proven performance optimization patterns. We will continue optimizing and porting the benchmark for new generations of FPGAs and design tools and encourage active participation to create a valuable tool for the community.}}, author = {{Meyer, Marius and Kenter, Tobias and Plessl, Christian}}, booktitle = {{2020 IEEE/ACM International Workshop on Heterogeneous High-performance Reconfigurable Computing (H2RC)}}, isbn = {{9781665415927}}, keywords = {{FPGA, OpenCL, High Level Synthesis, HPC benchmarking}}, title = {{{Evaluating FPGA Accelerator Performance with a Parameterized OpenCL Adaptation of Selected Benchmarks of the HPCChallenge Benchmark Suite}}}, doi = {{10.1109/h2rc51942.2020.00007}}, year = {{2020}}, } @article{12878, abstract = {{In scientific computing, the acceleration of atomistic computer simulations by means of custom hardware is finding ever-growing application. A major limitation, however, is that the high efficiency in terms of performance and low power consumption entails the massive usage of low precision computing units. Here, based on the approximate computing paradigm, we present an algorithmic method to compensate for numerical inaccuracies due to low accuracy arithmetic operations rigorously, yet still obtaining exact expectation values using a properly modified Langevin-type equation.}}, author = {{Rengaraj, Varadarajan and Lass, Michael and Plessl, Christian and Kühne, Thomas}}, journal = {{Computation}}, number = {{2}}, publisher = {{MDPI}}, title = {{{Accurate Sampling with Noisy Forces from Approximate Computing}}}, doi = {{10.3390/computation8020039}}, volume = {{8}}, year = {{2020}}, } @inproceedings{20695, author = {{Boeddeker, Christoph and Nakatani, Tomohiro and Kinoshita, Keisuke and Haeb-Umbach, Reinhold}}, booktitle = {{ICASSP 2020 - 2020 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)}}, isbn = {{9781509066315}}, title = {{{Jointly Optimal Dereverberation and Beamforming}}}, doi = {{10.1109/icassp40776.2020.9054393}}, year = {{2020}}, } @article{20580, author = {{Ma, Xuekai and Berger, B and Aßmann, M and Driben, R and Meier, Torsten and Schneider, C and Höfling, S and Schumacher, Stefan}}, issn = {{2041-1723}}, journal = {{Nature Communications}}, number = {{1}}, pages = {{897}}, title = {{{Realization of all-optical vortex switching in exciton-polariton condensates}}}, doi = {{10.1038/s41467-020-14702-5}}, volume = {{11}}, year = {{2020}}, } @article{20581, author = {{Pukrop, Matthias and Schumacher, Stefan and Ma, Xuekai}}, journal = {{Physical Review B}}, number = {{20}}, pages = {{205301}}, publisher = {{American Physical Society}}, title = {{{Circular polarization reversal of half-vortex cores in polariton condensates}}}, doi = {{10.1103/PhysRevB.101.205301}}, volume = {{101}}, year = {{2020}}, } @article{20583, author = {{Ma, Xuekai and Kartashov, Yaroslav V. and Gao, Tingge and Torner, Lluis and Schumacher, Stefan}}, journal = {{Physical Review B}}, number = {{4}}, pages = {{045309}}, publisher = {{American Physical Society}}, title = {{{Spiraling vortices in exciton-polariton condensates}}}, doi = {{10.1103/PhysRevB.102.045309}}, volume = {{102}}, year = {{2020}}, } @article{29744, abstract = {{A hole transfer from an excited Ru unit towards graphene oxide significantly improved the photocatalytic activity of the complexes.
}}, author = {{Rosenthal, Marta and Lindner, Jörg and Gerstmann, Uwe and Meier, Armin and Schmidt, Wolf Gero and Wilhelm, René}}, issn = {{2046-2069}}, journal = {{RSC Advances}}, keywords = {{General Chemical Engineering, General Chemistry}}, number = {{70}}, pages = {{42930--42937}}, publisher = {{Royal Society of Chemistry (RSC)}}, title = {{{A photoredox catalysed Heck reaction via hole transfer from a Ru(ii)-bis(terpyridine) complex to graphene oxide}}}, doi = {{10.1039/d0ra08749a}}, volume = {{10}}, year = {{2020}}, }