MASSIVELY-PARALLEL SELF-CONSISTENT-FIELD CALCULATIONS

The advent of supercomputers with many computational nodes each with i ts own independent memory makes possible very fast computations. Our w ork is focused on the development of electronic structure techniques f or the solution of Grand Challenge-size molecules containing hundreds of atoms. Our efforts have resulted in a scalable direct-SCF (self-con sistent-field) Fock matrix construction kernel that is portable and ef ficient. Good parallel performance is obtained by allowing asynchronou s communications and using a distributed data model. These requirement s are easily handled by using the Global Array (GA) software library d eveloped for this project. This algorithm has been incorporated into t he new program NWChem.