ct700223r_si_002.pdf (232.34 kB)
Electrostatically Embedded Many-Body Expansion for Simulations
journal contribution
posted on 2008-01-08, 00:00 authored by Erin E. Dahlke, Donald G. TruhlarWe have applied the electrostatically embedded
many-body (EE-MB) method truncated at the two-body
level (also called the pairwise additive EE-MB method or
the EE-PA approximation) and the three-body level (called
EE-3B) to calculate the gradient of the potential energy
for a simulation box containing 64 water molecules. We
employed the B3LYP density functional with the 6-31+G(d,p) basis set for this test case. We found that the EE-PA
method is able to reproduce the magnitude of the gradient
from a B3LYP/6-31+G(d,p) calculation on the entire
system to within 1.0% with a 1.3% error for the maximum
component of the gradient. Furthermore, the EE-3B method
is able to reproduce the magnitude of the gradient to within
0.1% with a 0.2% error for the maximum component of
the gradient. The good performance of the EE-MB methods for calculating forces and the highly parallel nature of
these methods make them well suited for use in molecular
dynamics simulations. Furthermore, since the methods can
be used for efficient and accurate calculations of forces
with any level of electronic structure theory that has analytic
gradients and with any electronic structure package that
allows for the presence of a field of point charges, these
methods can readily be used with a wide variety of density
functional theory and wave function theory methods.