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Comparison of methods for determining the correlation contribution to hydrogen bond energies
Author(s) -
Del Bene Janet E.,
Shavitt Isaiah
Publication year - 2009
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560360846
Subject(s) - supermolecule , coupled cluster , perturbation theory (quantum mechanics) , chemistry , electronic correlation , binding energy , consistency (knowledge bases) , configuration interaction , møller–plesset perturbation theory , function (biology) , computational chemistry , atomic physics , physics , molecule , quantum mechanics , mathematics , geometry , evolutionary biology , biology
The correlation energy contributions to the hydrogen bond energies of complexes (A 2 H 2n+1 ) + , A 2 H 2n , and (A 2 H 2n–1 ) − for AH n = OH 2 , FH, ClH have been evaluated using Møller–Plesset perturbation theory at second (MP2), third (MP3), and fourth (MP4) order; configuration interaction including all single and double excitations (CISD); the averaged coupled‐pair functional method (ACPF); and the linearized coupled‐cluster method (LCCM), all relative to a single‐reference Hartree–Fock function. The CISD energies were corrected for size‐consistency errors using the Pople formula and several variants of the Davidson correction and by use of the supermolecule approach for evaluating the binding energies. The Pople formula reduces the size‐consistency errors to less than 1 kcal/mol, and the supermolecule approach brings the CISD binding energies, even without correction, into reasonable agreement with the size‐consistent methods. The ACPF energies are found to be essentially size consistent in all the complexes studied. Both ACPF and LCCM provide binding energies very close to those of MP3.