PGAS-FMO Proxy Application

Short Description
This proxy application simulates the compute load and data-movement of the kernel of the Fragment Molecular Orbital (FMO) method in quantum chemistry. The proxy implements a parallel global address space (PGAS) in order to support FMO.
Argonne National Laboratory
Parent Application/Code
quantum chemistry, fragment molecular orbital
Programming Languages/Paradigms
fortran-90+ / MPI
Release/Version Number
Detailed description
This proxy app models the Fragment Molecular Orbital (FMO) method in Quantum Chemistry. FMO can compute very large systems with thousands of atoms using ab initio wave functions by first subdividing a system into smaller parts or fragments. The total energy is then expanded as a series in the fragments starting with the monomers, then the dimers, and so on. The approach derives its efficiency from neglect of inter-fragment exchange (‘nearsightedness’ principle) – an approximation managed by careful extension of the series and other model factors. Key to the HPC strategy of FMO is the implementation of a parallel global address space (PGAS) to distribute fragment data over the compute nodes. The present app computes the electron-repulsion term of the FMO monomer potential at the Hartree-Fock level, incorporating the medium- and long-range approximations to the coulomb interaction that are employed in real FMO applications. To the end-user this proxy provides insights into both the FMO method and the implementation of PGAS concepts.