A Pvm Implementation of the Mchf Atomic Structure Package

Abstract

The Multiconfiguration Hartree-Fock (MCHF) package is a suite of programs that provide the atomic data re quired by many science and engineering disciplines. Previous implementations of the MCHF on parallel computers provided means for meeting the ever- increasing computational demands posed by these calculations. However, the resulting codes had strict limitations on speed, problem size, and communication. In this paper, a Parallel Virtual Machine (PVM) imple mentation of the MCHF is considered on a cluster of high-end workstations. Some of the limitations are overcome through the high utilization of resources (in cluding CPU, prime memory, and disk space). The de velopment of efficient routines for global operations and of a user-friendly interface exploits the special characteristics of PVM programming. Moreover, a re structuring of the methods provides new codes that do not bear the above limitations and that exhibit signifi cantly better speedups. Besides the algorithmic im provements, this paper presents a flexible code that can be used equally well on workstations and on the IBM SP2 multiprocessor to solve problems of one or der of magnitude larger than any previous attempts, and thus facilitates new research in various scientific fields.