Configuration interaction approaches for solving quantum impurity models

TL;DR

This paper introduces configuration interaction methods to model the electronic structure of an adsorbate on a metal surface, focusing on the Anderson impurity model, with potential extensions to ab initio Hamiltonians for better understanding molecule-metal interactions.

Contribution

The paper develops new configuration interaction approaches specifically for the Anderson impurity model, aiming to improve the description of electron correlations in molecule-metal systems.

Findings

Methods achieve reasonable correlation description for the impurity model

Potential for extension to ab initio Hamiltonians

Provides insights into molecule-metal surface interactions

Abstract

We develop several configuration interaction approaches for characterizing the electronic structure of an adsorbate on a metal surface (at least in model form). When one can separate adsorbate from substrate, these methods can achieve a reasonable description of adsorbate on-site electron-electron correlation in the presence of a continuum of states. While the present paper is restricted to the Anderson impurity model, there is hope that these methods can be extended to ab initio Hamiltonians, and provide insight into the structure and dynamics of molecule-metal surface interactions.