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An examination of a density functional/molecular mechanical coupled potential
Author(s) -
Stanton Robert V.,
Hartsough David S.,
Merz Kenneth M.
Publication year - 1995
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.540160110
Subject(s) - hamiltonian (control theory) , solvation , scaling , potential energy , ion , statistical physics , series (stratigraphy) , chemistry , perturbation theory (quantum mechanics) , density functional theory , perturbation (astronomy) , physics , computational chemistry , molecular physics , atomic physics , quantum mechanics , mathematics , mathematical optimization , paleontology , geometry , biology
Abstract In this article we describe the coupling of a density functional (DF) Hamiltonian with the molecular mechanics (MM) potential function AMBER. We examine a series of test cases in which we compare the binding energies and geometries of the complexes predicted by this coupled potential with those predicted by other theoretical methods and experiment to establish the relative accuracy of the DF/MM coupled potential. We find that the DF/MM coupled potential performs well in most cases studied and, in general, outperforms the semiempirical/MM approach. The interaction energies and structures obtained using this method appear to be insensitive to the use of nonlocal (NL) corrections to the DF method. The is fortuitous because the NL treatment is significantly more computationally expensive than the local treatment. However, NL corrections may be required to predict accurately the shape of potential energy surfaces that involve bond breaking and formation. The DF/MM method has also been applied to the determination of the solvation free energy for a series of ions using free‐energy perturbation methods. The results obtained are good and can be improved by a simple scaling of the Lennard‐Jones parameters for the ion in question. © 1995 by John Wiley & Sons, Inc.