An efficient MPI/OpenMP parallelization of the Hartree-Fock method for the second generation of Intel® Xeon Phi™ processor

Modern OpenMP threading techniques are used to convert the MPI-only Hartree-Fock code in the GAMESS program to a hybrid MPI/OpenMP algorithm. Two separate implementations that differ by the sharing or replication of key data structures among threads are considered, density and Fock matrices. All implementations are benchmarked on a super-computer of 3,000 Intel® Xeon Phi
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processors. With 64 cores per processor, scaling numbers are reported on up to 192,000 cores. The hybrid MPI/OpenMP implementation reduces the memory footprint by approximately 200 times compared to the legacy code. The MPI/OpenMP code was shown to run up to six times faster than the original for a range of molecular system sizes. CCS CONCEPTS •Theory of computation → Massively parallel algorithms; •Computing methodologies → Rantum mechanic simulation; Massively parallel and high-performance simulations;