An Estimation of Hybrid Quantum Mechanical Molecular Mechanical Polarization Energies for Small Molecules Using Polarizable Force-Field Approaches

Journal Article · Tue Jan 24 00:00:00 EST 2017 · Journal of Chemical Theory and Computation

DOI:https://doi.org/10.1021/acs.jctc.6b01125· OSTI ID:1342645

Huang, Jing; Mei, Ye; König, Gerhard; Simmonett, Andrew C.; Pickard, Frank C.; Wu, Qin ; Wang, Lee-Ping ; MacKerell, Alexander D. ; Brooks, Bernard R.; Shao, Yihan

Here 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 R² value of 0.71 for aniline (in 10,000 TIP3P water configurations) and 0.87 or higher for other eleven solute molecules, while the PAD model has a much better performance with R² 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. Lastly, 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.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0012704; SC0011297; GM096678-02; GM072558; GM051501
• OSTI ID: 1342645
• Report Number(s): BNL-113460-2017-JA; R&D Project: 16068; KC0403020
• Journal Information: Journal of Chemical Theory and Computation, Vol. 13, Issue 2; ISSN 1549-9618
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

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