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An examination of the effects of basis set and charge transfer in hydrogen‐bonded dimers with a constrained Hartree–Fock method
Author(s) -
Cullen John M.
Publication year - 1991
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.560400821
Subject(s) - counterpoise , basis set , sto ng basis sets , chemistry , hartree–fock method , atomic orbital , linear combination of atomic orbitals , molecular orbital , intramolecular force , charge (physics) , atomic physics , basis (linear algebra) , intermolecular force , slater type orbital , localized molecular orbitals , molecular physics , computational chemistry , quantum mechanics , molecule , physics , density functional theory , electron , stereochemistry , geometry , mathematics , organic chemistry
Abstract Constrained Hartree–Fock methods in which orbitals are constructed from strictly local nonorthogonal subsets of the molecule's atomic orbital basis have been known for over a decade. These methods have been principally used to generate localized molecular orbitals and interpret intramolecular interactions. In this paper, constrained Hartree–Fock results from basis sets ranging from minimal to extensive are presented for hydrogen‐bonded dimers in which individual molecular orbitals are constructed from atomic orbitals belonging to individual monomers. These calculations eliminate both basis set superposition errors (BSSE) as well as charge transfer between monomers. This allows one to examine the effects of basis sets on the electrostatic and polarization components to the energy unmasked from BSSE. The charge transfer components are also isolated by comparing results to unconstrained calculations near the Hartree–Fock limit, where BSSE is vanishingly small. Finally, at moderate intermolecular separations when charge transfer becomes negligible, the constrained results are compared to both counterpoise‐corrected and unconstrained calculations.