AB INITIO QUANTUM CHEMISTRY ON PARALLEL AND DISTRIBUTED COMPUTERS WITH GAUSSIAN 92

THIS RESEARCH EXPLORES THE ISSUES INVOLVED IN PARALLELIZING GAUSSIAN 92, THE MOST WIDELY USED ELECTRONIC STRUCTURE SOFTWARE PACKAGE, USING THE LINDA PROGRAMMING ENVIRONMENT FOR WORKSTATION NETWORKS AND MULTIPROCESSORS. SINCE BOTH GAUSSIAN 92 AND LINDA EMPHASIZE PORTABILITY ACROSS MULTIPLE COMPUTER ARCHITECTURES, THIS PROJECT OFFERS CHEMISTS ELECTRONIC STRUCTURE MODELING WITH THE POWER OF PARALLEL PROCESSING WHILE RETAINING BOTH THE RANGE OF MODELS OFFERED BY GAUSSIAN AND THE CHOICE OF THE MOST COST-EFFECTIVE PLATFORM FOR EACH USER. AT SOME SITES, OTHERWISE IDLE CYCLES ON EXISTING WORKSTATION LANS PROVIDE A MAJOR SOURCE OF NEW AND PRODUCTIVE COMPUTING CAPACITY WHICH CAN BE UTILIZED AS A RESULT OF THIS EFFORT. THE KEY KERNELS OF THE ALGORITHMS IN GAUSIAN FOR VARIOUS MODELS ARE IDENTIFIED, AND METHODS DEVELOPED OF PARALLELIZING THESE COMPUTATION WHILE RETAINING THEIR HIGH EFFICIENCY ON INDIVIDUAL PROCESSORS. THE RESEARCH DEMONSTRATES THE FEASIBILITY OF USING LINDA ON WORKSTATION NETWORKS FOR THIS PURPOSE ON ONE CRITICAL TYPE OF MODEL, HARTREE-FOCK (INCLUDING GRADIENTS AND SECOND DERIVATIVES), IDENTIFY THE KEY KERNELS OF THE OTHER MODELS, AND DEVELOP A STRATEGY FOR PARALLELIZING THEM.