Parallel calculations of molecular properties Original Research Article

We discuss aspects of the parallelization of the Dalton quantum chemistry program, with particular emphasis on the calculation of second- and higher-order properties for large molecules. Our treatment includes real and imaginary perturbations, both frequency-dependent and static. The scaling behaviour of our approach, which is rather coarse-grained, is examined on different parallel platforms, including the Cray-T3E and an IBM SP with the latest multiprocessor nodes. The excellent scaling behaviour on the latter is especially significant given that the first TFLOPS computer available to the US academic community will be built from these nodes and deployed here at San Diego Supercomputer Center before the end of 1999. We then discuss applications of the code to several areas of interest in chemical physics.