AN EFFICIENT IMPLEMENTATION OF THE DIRECT-SCF ALGORITHM ON PARALLEL COMPUTER ARCHITECTURES

The development and implementation of a parallel direct self consistent field (SCF) Hartree-Fock algorithm, with gradients and random phase approximation solutions is presented. Important details of the structure of the parallel version of DISCO and preliminary results for calculations using the Concurrent Supercomputing Consortium Intel Touchstone Delta parallel computer system are reported. The data show that the algorithms are efficiently parallelized and that throughput of a one processor CRAY X-MP is reached with about 16 nodes on the Delta. The data also indicate sequential code which was not a bottleneck on traditional supercomputers, can become time critical on parallel computers.