Communication: Acceleration of coupled cluster singles and doubles via orbital-weighted least-squares tensor hypercontraction

Abstract

We apply orbital-weighted least-squares tensor hypercontraction decomposition of the electron repulsion integrals to accelerate the coupled cluster singles and doubles (CCSD) method. Using accurate and flexible low-rank factorizations of the electron repulsion integral tensor, we are able to reduce the scaling of the most vexing particle-particle ladder term in CCSD from O(N6) to O(N5), with remarkably low error. Combined with a T1-transformed Hamiltonian, this leads to substantial practical accelerations against an optimized density-fitted CCSD implementation. © 2014 AIP Publishing LLC.