Holomorphic Hartree-Fock Theory and Configuration Interaction

TL;DR

This paper introduces Holomorphic Hartree-Fock theory, a novel approach that modifies SCF equations to maintain solutions across geometries, enabling a smooth non-orthogonal configuration interaction for accurate molecular binding curves.

Contribution

The paper presents a new Holomorphic Hartree-Fock method that prevents solution disappearance, improving the stability of electronic structure calculations across molecular geometries.

Findings

Holomorphic Hartree-Fock solutions exist across all geometries.

The method produces smooth binding curves for H2.

Enhanced stability of SCF solutions in molecular calculations.

Abstract

We investigate the Hartree-Fock solutions to H2 in a minimal basis. We note the properties of the solutions and their disappearance with geometry and propose a new method, Holomorphic Hartree-Fock theory, where we modify the SCF equations to avoid disappearance of the solutions. We use these solutions as a basis for a non-orthogonal Configuration Interaction to produce a smooth binding curve over a complete range of geometries.