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A combined effective fragment potential-fragment molecular orbital method. I. The energy expression and initial applications

TitleA combined effective fragment potential-fragment molecular orbital method. I. The energy expression and initial applications
Publication TypeJournal Article
Year of Publication2009
AuthorsNagata T, Fedorov DG, Kitaura K, Gordon MS
Journal TitleJournal of Chemical Physics
Volume131
Pages024101
Date Published07/14
ISBN Number0021-9606
Accession NumberISI:000267983100003
Keywordsclosed-shell molecules, density-functional theory, distributed data interface, electronic-structure, geometry optimizations, intermolecular pauli repulsion, method fmo, ovomucoid 3rd domain, polarizable continuum model, theoretical-analysis
Abstract

The effective fragment potential (EFP) method, a model potential for treating solvent effects and other intermolecular interactions, is interfaced with an electronic structure method, the fragment molecular orbital (FMO) method, that is able to retain high accuracy for ab initio calculations on large molecular systems. The accuracy of the total energies in this novel combined FMO/EFP method is assessed by comparisons with the conventional quantum mechanics (QM)/EFP method. The test cases are water clusters, a peptide, and a dianionic protein (treated with full QM and FMO combined with water clusters (treated with EFP) at the RHF, B3LYP, and MP2 levels of theory. The basis sets employed range from minimal to augmented double zeta plus polarization. The energy differences between FMO/EFP and the conventional QM/EFP methods are within "chemical accuracy" (1 kcal/mol approximate to 4 kJ/mol). (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3156313]
URL<Go to ISI>://000267983100003
DOI10.1063/1.3156313