Quantum chemistry with an attached processor

The Floating Point Systems, Inc. Model 164 Attached Processor (FPS‐164) is a high‐speed, pipelined, parallel processor designed for large‐scale scientific computation. Benchmark studies of operations common in quantum chemistry codes are discussed and the performance of the FPS‐164 is compared with other commonly available computers. A complete system of electronic structure codes has been implemented on the FPS‐164 using the Fortran‐77 cross‐compiler and calls to optimized vector and matrix routines. The conversion of a generalized valence bond (GVB) code illustrates the strategy adopted to adapt Fortran codes to the FPS‐164. A typical production example, a large scale (GVB) and configuration interaction calculation on the vinyl radical, shows a net throughput equivalent to nearly nine VAX 11/780 computers.