Cutoff-Based Modeling of Coulomb Interactions for Atomistic-to-Continuum Multiscale Methods
V. Boddu, D. Davydov, B. Eidel and P. Steinmann
Multiscale Science and Engineering, 1, 299-317 (2019).

ABSTRACT
Atomic interactions in a large class of functional materials, essentially—all
dielectrics, polarizable solids and ionic solids, involve long-range Coulomb
interactions. Yet atomistic-to-continuum multiscale methods, such as the
quasicontinuum method, are currently applicable only in cases where the atomic
interactions are short-ranged. This restriction on the nature of atomic-level
interactions for multiscale methods excludes numerous materials that are central
to various scientific and industrial applications. A number of studies have
pointed out unphysical artifacts in molecular simulations upon using the direct
cutoff-based truncated sum to evaluate Coulomb interactions in ionic solids.
However, recently it is understood that the artifacts of the direct cutoff-based
truncated sum can be significantly minimized if a suitable correction term is
added. In this work we examine whether or not the Wolf summation method, one of
the prominent cutoff-based methods, is suitable to carry out the accumulation of
the Coulomb interactions within the context of atomistic-to-continuum multiscale
methods. In this regard, we choose the quasicontinuum method from the existing
collection of multiscale methods for demonstration. It is found that the Wolf
summation method can be applied if the atomistic system has charge ordering;
otherwise, the error in the accumulation of the Coulomb interactions could be
large.