Parallel Algorithms for Coupled Cluster Calculations

Edgar Solomonik, University of California, Berkeley

I will present parallel algorithms for tensor contractions, which arise in the context of the coupled cluster family of methods in electronic structure theory. Coupled cluster provides the most exact methods for quantum chemical calculations on medium-sized molecules and electronic systems with high quantum correlation. The methods are computationally expensive and calculations even of small chemical systems require HPC resources. I will present an algorithmic framework that provides parallel algorithms that exploit high-dimensional symmetry in the coupled cluster contractions, significantly lowering the computational and communication costs. My implementation of these algorithms is called Cyclops Tensor Framework (CTF). Using CTF on the Blue Gene/Q supercomputer, we have been able to do computations of the coupled cluster method with single and double electron excitations (CCSD) at a larger scale than ever done before. Higher-order coupled cluster methods and exploitation of tensor sparsity are currently in development.

Abstract Author(s): Edgar Solomonik