TY - GEN AB - Electronic structure calculations have been instrumental in providing many important insights into a range of physical and chemical properties of various molecular and solid-state systems. Their importance to various fields, including materials science, chemical sciences, computational chemistry and device physics, is underscored by the large fraction of available public supercomputing resources devoted to these calculations. As we enter the exascale era, exciting new opportunities to increase simulation numbers, sizes, and accuracies present themselves. In order to realize these promises, the community of electronic structure software developers will however first have to tackle a number of challenges pertaining to the efficient use of new architectures that will rely heavily on massive parallelism and hardware accelerators. This roadmap provides a broad overview of the state-of-the-art in electronic structure calculations and of the various new directions being pursued by the community. It covers 14 electronic structure codes, presenting their current status, their development priorities over the next five years, and their plans towards tackling the challenges and leveraging the opportunities presented by the advent of exascale computing. AU - Gavini, Vikram AU - Baroni, Stefano AU - Blum, Volker AU - Bowler, David R. AU - Buccheri, Alexander AU - Chelikowsky, James R. AU - Das, Sambit AU - Dawson, William AU - Delugas, Pietro AU - Dogan, Mehmet AU - Draxl, Claudia AU - Galli, Giulia AU - Genovese, Luigi AU - Giannozzi, Paolo AU - Giantomassi, Matteo AU - Gonze, Xavier AU - Govoni, Marco AU - Gulans, Andris AU - Gygi, François AU - Herbert, John M. AU - Kokott, Sebastian AU - Kühne, Thomas AU - Liou, Kai-Hsin AU - Miyazaki, Tsuyoshi AU - Motamarri, Phani AU - Nakata, Ayako AU - Pask, John E. AU - Plessl, Christian AU - Ratcliff, Laura E. AU - Richard, Ryan M. AU - Rossi, Mariana AU - Schade, Robert AU - Scheffler, Matthias AU - Schütt, Ole AU - Suryanarayana, Phanish AU - Torrent, Marc AU - Truflandier, Lionel AU - Windus, Theresa L. AU - Xu, Qimen AU - Yu, Victor W. -Z. AU - Perez, Danny ID - 33493 T2 - arXiv:2209.12747 TI - Roadmap on Electronic Structure Codes in the Exascale Era ER - TY - CONF AU - Karp, Martin AU - Podobas, Artur AU - Kenter, Tobias AU - Jansson, Niclas AU - Plessl, Christian AU - Schlatter, Philipp AU - Markidis, Stefano ID - 46193 T2 - International Conference on High Performance Computing in Asia-Pacific Region TI - A High-Fidelity Flow Solver for Unstructured Meshes on Field-Programmable Gate Arrays: Design, Evaluation, and Future Challenges ER - TY - GEN AB - The CP2K program package, which can be considered as the swiss army knife of atomistic simulations, is presented with a special emphasis on ab-initio molecular dynamics using the second-generation Car-Parrinello method. After outlining current and near-term development efforts with regards to massively parallel low-scaling post-Hartree-Fock and eigenvalue solvers, novel approaches on how we plan to take full advantage of future low-precision hardware architectures are introduced. Our focus here is on combining our submatrix method with the approximate computing paradigm to address the immanent exascale era. AU - Kühne, Thomas AU - Plessl, Christian AU - Schade, Robert AU - Schütt, Ole ID - 32404 T2 - arXiv:2205.14741 TI - CP2K on the road to exascale ER - TY - GEN AB - Electronic structure calculations have been instrumental in providing many important insights into a range of physical and chemical properties of various molecular and solid-state systems. Their importance to various fields, including materials science, chemical sciences, computational chemistry and device physics, is underscored by the large fraction of available public supercomputing resources devoted to these calculations. As we enter the exascale era, exciting new opportunities to increase simulation numbers, sizes, and accuracies present themselves. In order to realize these promises, the community of electronic structure software developers will however first have to tackle a number of challenges pertaining to the efficient use of new architectures that will rely heavily on massive parallelism and hardware accelerators. This roadmap provides a broad overview of the state-of-the-art in electronic structure calculations and of the various new directions being pursued by the community. It covers 14 electronic structure codes, presenting their current status, their development priorities over the next five years, and their plans towards tackling the challenges and leveraging the opportunities presented by the advent of exascale computing. AU - Gavini, Vikram AU - Baroni, Stefano AU - Blum, Volker AU - Bowler, David R. AU - Buccheri, Alexander AU - Chelikowsky, James R. AU - Das, Sambit AU - Dawson, William AU - Delugas, Pietro AU - Dogan, Mehmet AU - Draxl, Claudia AU - Galli, Giulia AU - Genovese, Luigi AU - Giannozzi, Paolo AU - Giantomassi, Matteo AU - Gonze, Xavier AU - Govoni, Marco AU - Gulans, Andris AU - Gygi, François AU - Herbert, John M. AU - Kokott, Sebastian AU - Kühne, Thomas AU - Liou, Kai-Hsin AU - Miyazaki, Tsuyoshi AU - Motamarri, Phani AU - Nakata, Ayako AU - Pask, John E. AU - Plessl, Christian AU - Ratcliff, Laura E. AU - Richard, Ryan M. AU - Rossi, Mariana AU - Schade, Robert AU - Scheffler, Matthias AU - Schütt, Ole AU - Suryanarayana, Phanish AU - Torrent, Marc AU - Truflandier, Lionel AU - Windus, Theresa L. AU - Xu, Qimen AU - Yu, Victor W. -Z. AU - Perez, Danny ID - 46275 T2 - arXiv:2209.12747 TI - Roadmap on Electronic Structure Codes in the Exascale Era ER - TY - CONF AU - Meyer, Marius ID - 27365 T2 - Proceedings of the 11th International Symposium on Highly Efficient Accelerators and Reconfigurable Technologies TI - Towards Performance Characterization of FPGAs in Context of HPC using OpenCL Benchmarks ER - TY - CONF AU - Nickchen, Tobias AU - Heindorf, Stefan AU - Engels, Gregor ID - 20886 T2 - Proceedings of the IEEE/CVF Winter Conference on Applications of Computer Vision TI - Generating Physically Sound Training Data for Image Recognition of Additively Manufactured Parts ER - TY - GEN AB - We push the boundaries of electronic structure-based \textit{ab-initio} molecular dynamics (AIMD) beyond 100 million atoms. This scale is otherwise barely reachable with classical force-field methods or novel neural network and machine learning potentials. We achieve this breakthrough by combining innovations in linear-scaling AIMD, efficient and approximate sparse linear algebra, low and mixed-precision floating-point computation on GPUs, and a compensation scheme for the errors introduced by numerical approximations. The core of our work is the non-orthogonalized local submatrix method (NOLSM), which scales very favorably to massively parallel computing systems and translates large sparse matrix operations into highly parallel, dense matrix operations that are ideally suited to hardware accelerators. We demonstrate that the NOLSM method, which is at the center point of each AIMD step, is able to achieve a sustained performance of 324 PFLOP/s in mixed FP16/FP32 precision corresponding to an efficiency of 67.7% when running on 1536 NVIDIA A100 GPUs. AU - Schade, Robert AU - Kenter, Tobias AU - Elgabarty, Hossam AU - Lass, Michael AU - Schütt, Ole AU - Lazzaro, Alfio AU - Pabst, Hans AU - Mohr, Stephan AU - Hutter, Jürg AU - Kühne, Thomas D. AU - Plessl, Christian ID - 32244 T2 - arXiv:2104.08245 TI - Towards Electronic Structure-Based Ab-Initio Molecular Dynamics Simulations with Hundreds of Millions of Atoms ER - TY - GEN AB - Optical travelling wave antennas offer unique opportunities to control and selectively guide light into a specific direction which renders them as excellent candidates for optical communication and sensing. These applications require state of the art engineering to reach optimized functionalities such as high directivity and radiation efficiency, low side lobe level, broadband and tunable capabilities, and compact design. In this work we report on the numerical optimization of the directivity of optical travelling wave antennas made from low-loss dielectric materials using full-wave numerical simulations in conjunction with a particle swarm optimization algorithm. The antennas are composed of a reflector and a director deposited on a glass substrate and an emitter placed in the feed gap between them serves as an internal source of excitation. In particular, we analysed antennas with rectangular- and horn-shaped directors made of either Hafnium dioxide or Silicon. The optimized antennas produce highly directional emission due to the presence of two dominant guided TE modes in the director in addition to leaky modes. These guided modes dominate the far-field emission pattern and govern the direction of the main lobe emission which predominately originates from the end facet of the director. Our work also provides a comprehensive analysis of the modes, radiation patterns, parametric influences, and bandwidths of the antennas that highlights their robust nature. AU - Farheen, Henna AU - Leuteritz, Till AU - Linden, Stefan AU - Myroshnychenko, Viktor AU - Förstner, Jens ID - 32245 T2 - arXiv:2106.02468 TI - Optimization of optical waveguide antennas for directive emission of light ER - TY - GEN AB - The interaction between quantum light and matter is being intensively studied for systems that are enclosed in high-$Q$ cavities which strongly enhance the light-matter coupling. However, for many applications, cavities with lower $Q$-factors are preferred due to the increased spectral width of the cavity mode. Here, we investigate the interaction between quantum light and matter represented by a $\Lambda$-type three-level system in lossy cavities, assuming that cavity losses are the dominant loss mechanism. We demonstrate that cavity losses lead to non-trivial steady states of the electronic occupations that can be controlled by the loss rate and the initial statistics of the quantum fields. The mechanism of formation of such steady states can be understood on the basis of the equations of motion. Analytical expressions for steady states and their numerical simulations are presented and discussed. AU - Rose, H. AU - Tikhonova, O. V. AU - Meier, T. AU - Sharapova, P. ID - 32236 T2 - arXiv:2109.00842 TI - Steady states of $Λ$-type three-level systems excited by quantum light in lossy cavities ER - TY - CONF AU - Kenter, Tobias AU - Shambhu, Adesh AU - Faghih-Naini, Sara AU - Aizinger, Vadym ID - 46194 T2 - Proceedings of the Platform for Advanced Scientific Computing Conference TI - Algorithm-hardware co-design of a discontinuous Galerkin shallow-water model for a dataflow architecture on FPGA ER -