For an ab initio calculation of the magnetic excitations: RelaxSE

In this paper, we present a novel efficient and parallel implementation, RelaxSE, for the calculation of the low-lying excited states and energies of strongly correlated systems. RelaxSE is based on the fully uncontracted multi-reference method of Selected Active Space + Single excitations. This met...

Full description

Saved in:
Bibliographic Details
Published inThe Journal of chemical physics Vol. 154; no. 16; p. 164116
Main Authors Rebolini, Elisa, Lepetit, Marie-Bernadette
Format Journal Article
LanguageEnglish
Published United States 28.04.2021
Online AccessGet more information

Cover

Loading…
More Information
Summary:In this paper, we present a novel efficient and parallel implementation, RelaxSE, for the calculation of the low-lying excited states and energies of strongly correlated systems. RelaxSE is based on the fully uncontracted multi-reference method of Selected Active Space + Single excitations. This method has been specifically designed to be able to tackle systems with numerous open shells per atoms. It is, however, computationally challenging due to the rapid scaling of the number of determinants and their non-trivial ordering induced by the selection process. We propose a combined determinant-driven and integral-driven approach designed for hybrid OpenMP/MPI parallelization. The performances of RelaxSE are evaluated on a controlled test set and show linear scaling with respect to the number of determinants and a small overhead due to the parallelization. Systems with up to 1 × 10 determinants are successfully computed.
ISSN:1089-7690
DOI:10.1063/5.0045672