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A computationally inexpensive modification of the point dipole electrostatic polarization model for molecular simulations
Author(s) -
Kaminski George A.,
Friesner Richard A.,
Zhou Ruhong
Publication year - 2003
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.10170
Subject(s) - chemistry , dipole , force field (fiction) , molecular dynamics , polarizability , computational chemistry , ab initio , monte carlo method , statistical physics , thermodynamics , physics , molecule , quantum mechanics , mathematics , organic chemistry , statistics
We present an approximation, which allows reduction of computational resources needed to explicitly incorporate electrostatic polarization into molecular simulations utilizing empirical force fields. The proposed method is employed to compute three‐body energies of molecular complexes with dipolar electrostatic probes, gas‐phase dimerization energies, and pure liquid properties for five systems that are important in biophysical and organic simulations—water, methanol, methylamine, methanethiol, and acetamide. In all the cases, the three‐body energies agreed with high level ab initio data within 0.07 kcal/mol, dimerization energies—within 0.43 kcal/mol (except for the special case of the CH 3 SH), and computed heats of vaporization and densities differed from the experimental results by less than 2%. Moreover, because the presented method allows a significant reduction in computational cost, we were able to carry out the liquid‐state calculations with Monte Carlo technique. Comparison with the full‐scale point dipole method showed that the computational time was reduced by 3.5 to more than 20 times, depending on the system in hand and on the desired level of the full‐scale model accuracy, while the difference in energetic results between the full‐scale and the presented approximate model was not great in the most cases. Comparison with the nonpolarizable OPLS‐AA force field for all the substances involved and with the polarizable POL3 and q90 models for water and methanol, respectively, demonstrates that the presented technique allows reduction of computational cost with no sacrifice of accuracy. We hope that the proposed method will be of benefit to research employing molecular modeling technique in the biophysical and physical organic chemistry areas. © 2003 Wiley Periodicals, Inc. J Comput Chem 24: 267–276, 2003