jz8b01412_si_001.pdf (2.65 MB)
QM/MM Simulations with the Gaussian Electrostatic Model: A Density-based Polarizable Potential
journal contribution
posted on 2018-05-18, 00:00 authored by Hatice Gökcan, Eric Kratz, Thomas A. Darden, Jean-Philip Piquemal, G. Andrés CisnerosThe use of advanced polarizable potentials
in quantum mechanical/molecular
mechanical (QM/MM) simulations has been shown to improve the overall
accuracy of the calculation. We have developed a density-based potential
called the Gaussian electrostatic model (GEM), which has been shown
to provide very accurate environments for QM wave functions in QM/MM.
In this contribution we present a new implementation of QM/GEM that
extends our implementation to include all components (Coulomb, exchange–repulsion,
polarization, and dispersion) for the total intermolecular interaction
energy in QM/MM calculations, except for the charge-transfer term.
The accuracy of the method is tested using a subset of water dimers
from the water dimer potential energy surface reported by Babin et
al. (J. Chem. Theory Comput. 2013 9, 5395–5403). Additionally, results of the new implementation
are contrasted with results obtained with the classical AMOEBA potential.
Our results indicate that GEM provides an accurate MM environment
with average root-mean-square error <0.15 kcal/mol for every intermolecular
interaction energy component compared with SAPT2+3/aug-cc-pVTZ reference
calculations.