Model density approach to Ewald summations

The evaluation of the electrostatic potential is fundamental to the study of condensed phase systems. We discuss the calculation of the relevant lattice summations by Ewald-type techniques. A model charge density is introduced, that cancels multipole moments of the crystalline charge distribution up to a desired order, for accelerating convergence of the Ewald sums. The method is applicable to calculations of bulk systems, employing arbitrary unit cells in a classical or quantum context, and with arbitrary basis functions to represent the charge density. The approach clarifies a decades-old implementation in the CRYSTAL code.

Source: arXiv:2601.21776v1 - http://arxiv.org/abs/2601.21776v1 PDF: https://arxiv.org/pdf/2601.21776v1 Original Link: http://arxiv.org/abs/2601.21776v1