Implicit infinite lattice summations for real space ab initio correlation methods

TL;DR

This paper introduces a novel local wave function based ab initio method for infinite periodic systems that explicitly accounts for both short-range and long-range correlation effects, using a reformulated lattice summation with elliptic theta functions.

Contribution

It develops a formalism to describe long-range polarization in infinite solids within a local wave function framework, employing a closed-form lattice summation using elliptic theta functions.

Findings

Successfully describes long-range polarization effects in LiH and LiF.

Reformulates lattice summation in a closed analytic form.

Demonstrates the method with numerical examples.

Abstract

We suggest a local wave function based ab initio correlation method for infinite periodic systems, which can describe both the near range as well as the long range correlation effects coherently in the same scheme. Specifically, this work introduces a formalism which allows to describe the long range polarization cloud around a quasi particle in a solid explicitly in the formalism of local wave function based ab initio descriptions. To this end we reformulate the infinite lattice summation underlying the quantum chemistry formula to second order in a closed analytic form employing the elliptic theta function of the third kind. All formulas and manipulations are developed explicitely in full detail and a first numeric example demonstrates the principle idea. Good results for the long range polarization effects in LiH and LiF are found in agreement with earlier estimates.