Atomic structure calculations on the CRAY X-MP

Atomic structure calculations require both radial and angular integrations, where the latter are often based on Racah algebra. With relatively minor modifications, good performance is obtained on vector machines for radial integrations. Angular integrations, however, present the bottleneck. In this paper some recent improvements in the algorithms for angular integrations are described, as well as some multitasking experiments on the CRAY X-MP and CRAY 2. These show that the workload can easily be distributed evenly among available processors with dynamic scheduling