Pushing configuration-interaction to the limit: Towards massively parallel MCSCF calculations

Konstantinos D. Vogiatzis, Dongxia Ma, Jeppe Olsen, Laura Gagliardi, Wibe A. De Jong

Research output: Contribution to journalArticle

32 Scopus citations

Abstract

A new large-scale parallel multiconfigurational self-consistent field (MCSCF) implementation in the open-source NWChem computational chemistry code is presented. The generalized active space approach is used to partition large configuration interaction (CI) vectors and generate a sufficient number of batches that can be distributed to the available cores. Massively parallel CI calculations with large active spaces can be performed. The new parallel MCSCF implementation is tested for the chromium trimer and for an active space of 20 electrons in 20 orbitals, which can now routinely be performed. Unprecedented CI calculations with an active space of 22 electrons in 22 orbitals for the pentacene systems were performed and a single CI iteration calculation with an active space of 24 electrons in 24 orbitals for the chromium tetramer was possible. The chromium tetramer corresponds to a CI expansion of one trillion Slater determinants (914 058 513 424) and is the largest conventional CI calculation attempted up to date.

Original languageEnglish (US)
Article number184111
JournalJournal of Chemical Physics
Volume147
Issue number18
DOIs
StatePublished - Nov 14 2017

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