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Combined Fragment Molecular Orbital Cluster in Molecule Approach to Massively Parallel Electron Correlation Calculations for Large Systems

TitleCombined Fragment Molecular Orbital Cluster in Molecule Approach to Massively Parallel Electron Correlation Calculations for Large Systems
Publication TypeJournal Article
Year of Publication2015
AuthorsFindlater, AD, Zahariev, F, Gordon, MS
JournalJournal of Physical Chemistry A
Volume119
Pagination3587-3593
Date Published04
Type of ArticleArticle
ISBN Number1089-5639
Accession NumberWOS:000353249300006
Keywordsaccurate calculations, coupled-cluster, implementation, invariant, local treatment, method fmo, plesset perturbation-theory, triples
Abstract

The local correlation cluster-in-molecule (CIM) method is combined with the fragment molecular orbital (FMO) method, providing a flexible, massively parallel, and near-linear scaling approach to the calculation of electron correlation energies for large molecular systems. Although the computational scaling of the CIM algorithm is already formally linear, previous knowledge of the HartreeFock (HF) reference wave function and subsequent localized orbitals is required; therefore, extending the CIM method to arbitrarily large systems requires the aid of low-scaling/linear-scaling approaches to HF and orbital localization. Through fragmentation, the combined FMO-CIM method linearizes the scaling, with respect to system size, of the HF reference and orbital localization calculations, achieving near-linear scaling at both the reference and electron correlation levels. For the 20-residue alanine a helix, the preliminary implementation of the FMO-CIM method captures 99.6% of the MP2 correlation energy, requiring 21% of the MP2 wall time. The new method is also applied to solvated adamantine to illustrate the multilevel capability of the FMO-CIM method.

DOI10.1021/jp509266g
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Chemical Physics

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PCTC Catalysis