A GENERAL PARALLEL SOLUTION TO THE INTEGRAL TRANSFORMATION AND 2ND-ORDER MOLLER-PLESSET ENERGY EVALUATION ON DISTRIBUTED-MEMORY PARALLEL MACHINES

We present here a parallel algorithm for four-index (integral) transfo rmation and second-order Moller-Plesset (MP2) energy evaluation, prima rily designed for multiple instruction multiple data (MIMD) machines. It is a general algorithm designed to work with-equal efficiency on an y inhomogeneous network and any architecture. This algorithm works wit h only a twofold redundancy in integral storage, whereas some previous ly reported strategies demand a fourfold redundancy. The parallel tran sformation and sorting algorithm has been implemented on a 128 node in homogeneous ring network, 64 of the processors being about 30%-40% slo wer. The present parallel scheme is seen-to perform excellently in int egral transformation processes even in such an inhomogeneous environme nt due to dynamic load balancing strategies. It has been found that in tegral transformation along with MP2 energy evaluation takes typically 120-200 min for molecules with 80-90 atomic orbitals However, time ta ken for such systems reduces to similar to 30-60 min when only requisi te partial transformation is carried out for MP2 energy evaluation.