title: Reduced-cost sparsity-exploiting algorithm for solving coupled-cluster equations.
abstract: We present an algorithm for reducing the computational work involved in coupled-cluster (CC) calculations by sparsifying the amplitude correction within a CC amplitude update procedure. We provide a theoretical justification for this approach, which is based on the convergence theory of inexact Newton iterations. We demonstrate by numerical examples that, in the simplest case of the CCD equations, we can sparsify the amplitude correction by setting, on average, roughly 90% nonzero elements to zeros without a major effect on the convergence of the inexact Newton iterations.
authors.affiliation: Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720.
authors.forename: Jiri
authors.initials: J
authors.lastname: Brabec
authors.affiliation: Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720.
authors.forename: Chao
authors.initials: C
authors.lastname: Yang
authors.affiliation: Department of Chemistry, University of Southern California, Los Angeles, California, 90089-0482.|Q-Chem Inc, Suite 105 Pleasanton, California, 94588.
authors.forename: Evgeny
authors.initials: E
authors.lastname: Epifanovsky
authors.affiliation: Department of Chemistry, University of Southern California, Los Angeles, California, 90089-0482.
authors.forename: Anna I
authors.initials: AI
authors.lastname: Krylov
authors.affiliation: Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720.
authors.forename: Esmond
authors.initials: E
authors.lastname: Ng
keywords: coupled-cluster methods; quasi-Newton; solvers; sparse correction; sparsity