Is the Ewald summation still necessary? Pairwise alternatives to the accepted standard for long-range electrostatics
Christopher J. Fennell and J. Daniel Gezelter *
Department of Chemistry and Biochemistry
University of Notre Dame
Notre Dame, Indiana 46556
We investigate pairwise electrostatic interaction methods and show
that there are viable computationally efficient (O(N)) alternatives to
the Ewald summation for typical modern molecular simulations. These
methods are extended from the damped and cutoff-neutralized Coulombic
sum originally proposed by Wolf et al. [J. Chem. Phys.
110, 8255 (1999)]. One of these, the damped shifted force
method, shows a remarkable ability to reproduce the energetic and
dynamic characteristics exhibited by simulations employing lattice
summation techniques. Comparisons were performed with this and other
pairwise methods against the smooth particle-mesh Ewald summation to
see how well they reproduce the energetics and dynamics of a variety
of molecular simulations.
