Scalability of correlated electronic structure calculations on parallel computers : A case study of the RI-MP2 method

摘要

The RI-MP2 method arises from the application of the “resolution of the identity” (RI) integral approximation to the second-order many-body perturbation theory (MP2). It pro- vides a lower-cost alternative to the MP2 method, widely used in the computational chemistry community. This paper describes the implementation of the Rl-MP2 method using the Global Array parallel programming model and analyzes its scalability, both with problem size and number of processors. Large-scale calculations are dominated by a parallel matrix multipli- cation, and scale quite well from 16 to 128 processors on an IBM RS/6000 SP system. It is estimated that exact MP2 calculations on the largest system reported here inight take as much as 90 times longer than the RI-MP2 timings presented.