Adiabatic connection interaction strength interpolation method made accurate for the uniform electron gas

TL;DR

This paper develops a refined adiabatic connection interaction strength interpolation (ISI) functional, called genISI, that accurately models the uniform electron gas, demonstrating high accuracy for solid-state and atomic systems, advancing correlation energy calculations.

Contribution

The paper introduces genISI, an improved ISI-like functional tailored for the uniform electron gas, enhancing correlation energy predictions in solid-state physics.

Findings

genISI is highly accurate for jellium spheres with up to 912 electrons

genISI performs well for noble atoms with Z up to 290

The method shows promise for solid-state calculations using ISI-like approaches

Abstract

The adiabatic connection interaction strength interpolation (ISI)-like method provides a high-level expression for the correlation energy, being in principle exact in the weak-interaction limit, where it recovers the second-order G\"orling-Levy perturbation term, but also in the strong-interaction limit that is described by the strictly correlated electron approach. In this work, we construct the genISI functional made accurate for the uniform electron gas, a solid-state physics paradigm that is a very difficult test for ISI-like correlation functionals. We assess the genISI functional for various jellium spheres with the number of electrons Z $\leq$ 912 and for the non-relativistic noble atoms with Z $\leq$ 290. For the jellium clusters, the genISI is remarkably accurate, while for the noble atoms, it shows a good performance, similar to other ISI-like methods. Then, the genISI functional can open the path using the ISI-like method in solid-state calculations.