THE LOCALLY SELF-CONSISTENT MULTIPLE-SCATTERING CODE IN A GEOGRAPHICALLY DISTRIBUTED LINKED MPP ENVIRONMENT

Oak Ridge National Laboratory (ORNL), Sandia National Laboratories (SN L), and Pittsburgh Supercomputing Center (PSC) are in the midst of a p roject through which their supercomputers are linked via high speed ne tworks. The overall goal of this project is to solve national security and scientific problems too large to run on any single available mach ine. This paper describes the infrastructure used in the linked comput ing environment and discusses issues related to porting and running th e Locally Self-consistent Multiple Scattering (LSMS) code in the linke d environment. In developing a geographically distributed heterogeneou s environment of high performance massively parallel processors (MPP) and porting code to it, a variety of problems were encountered and sol ved. Comparative performance measurements for the LSMS on a single mac hine and across linked machines are given along with an interpretation of the results. (C) 1998 Elsevier Science B.V. All rights reserved.