Implementation and applications of Gaussian 82 on a CDC Cyber 205

The implementation of the GAUSSIAN 82 system of quantum chemistry codes on the CDC Cyber 205 supercomputer required approximately 1 1/2 man years of effort. Idiosyncracies of the Cyber 205 architecture, operating system, and compiler in so far as they affect the conversion and operation of large quantum chemistry codes on the machine are described. While advantage has not been taken of the powerful vector processor, the high intrinsic speed of the scalar processor and the large virtual storage capacity of the Cyber 205 make it a very powerful research tool for computational chemistry. The impact of the GAUSSIAN 82/Cyber 205 combination on computational chemistry research at the University of Calgary is illustrated by brief descriptions of a range of applications from highly accurate calculations on small systems to semiempirical studies of large molecular aggregates. Complete geometry optimizations and harmonic frequency analyses, for the most part, have become routine.