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Atom–atom partitioning of total (super)molecular energy: The hidden terms of classical force fields
Author(s) -
Rafat M.,
Popelier P. L. A.
Publication year - 2006
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.20530
Subject(s) - atom (system on chip) , force field (fiction) , total energy , chemistry , computational chemistry , atomic physics , physics , computer science , quantum mechanics , embedded system , psychology , displacement (psychology) , psychotherapist
Classical force fields describe the interaction between atoms that are bonded or nonbonded via simple potential energy expressions. Their parameters are often determined by fitting to ab initio energies and electrostatic potentials. A direct quantum chemical guide to constructing a force field would be the atom–atom partitioning of the energy of molecules and van der Waals complexes relevant to the force field. The authors used the theory of quantum chemical topology to partition the energy of five systems [H 2 , CO, H 2 O, (H 2 O) 2 , and (HF) 2 ] in terms of kinetic, Coulomb, and exchange intra‐atomic and interatomic contributions. The authors monitored the variation of these contributions with changing bond length or angle. Current force fields focus only on interatomic interaction energies and assume that these purely potential energy terms are the only ones that govern structure and dynamics in atomistic simulations. Here the authors highlight the importance of self‐energy terms (kinetic and intra‐atomic Coulomb and exchange). © 2006 Wiley Periodicals, Inc. J Comput Chem 2007