An Estimation of Hybrid Quantum Mechanical Molecular Mechanical Polarization Energies for Small Molecules Using Polarizable Force-Field Approaches
Year: 2017
Type: article
Abstract: In this work, we report two polarizable molecular mechanics (polMM) force field models for estimating the polarization energy in hybrid quantum mechanical molecular mechanical (QM/MM) calculations. These two models, named the potential of atomic charges (PAC) and potential of atomic dipoles (PAD), are formulated from the ab initio quantum mechanical (QM) response kernels for the prediction of the QM density response to an external molecular mechanical (MM) environment (as described by external point charges). The PAC model is similar to fluctuating charge (FQ) models because the energy depends on external electrostatic potential values at QM atomic sites; the PAD energy depends on external electrostatic field values at QM atomic sites, resembling induced dipole (ID) models. To demonstrate their uses, we apply the PAC and PAD models to 12 small molecules, which are solvated by TIP3P water. The PAC model reproduces the QM/MM polarization energy with a R 2 value of 0.71 for aniline (in 10,000 TIP3P water configurations) and 0.87 or higher for other 11 solute molecules, while the PAD model has a much better performance with R 2 values of 0.98 or higher. The PAC model reproduces reference QM/MM hydration free energies for 12 solute molecules with a RMSD of 0.59 kcal/mol. The PAD model is even more accurate, with a much smaller RMSD of 0.12 kcal/mol, with respect to the reference. This suggests that polarization effects, including both local charge distortion and intramolecular charge transfer, can be well captured by induced dipole type models with proper parametrization.
Institutions: University of Maryland, Baltimore, National Institutes of Health, National Heart, Lung, and Blood Institute, New York University Shanghai, East China Normal University, Max-Planck-Institut für Kohlenforschung, Brookhaven National Laboratory, Center for Functional Nanomaterials, University of California, Davis, Q Chem (United States), University of Oklahoma
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G1027745422, Efficient double hybrid density functional theory algorithms for conformational a, Polarizable Force Field for Proteins and Lipids, Oligonucleotide Conformational Heterogeneity, G257819028, Efficient double hybrid density functional theory algorithms for conformational a, HALOGEN FREE ENERGY DATABASE FOR RATIONAL DRUG DESIGN, G8272007162, G8358207457
OpenAlex ID: W2572840298