The interaction-strength interpolation method for main-group chemistry: benchmarking, limitations, and perspectives

TL;DR

This paper evaluates the interaction-strength-interpolation (ISI) functional for main-group chemistry, analyzing its performance, limitations, and potential applications in dispersion-bonded complexes.

Contribution

It provides a comprehensive benchmarking of the ISI functional, highlighting its strengths and limitations in various chemical scenarios.

Findings

Good performance for dispersion-bonded complexes when used as a correction

Limitations in atomization energy calculations

Dependence on basis sets and ground-state orbitals

Abstract

We have tested the original interaction-strength-interpolation (ISI) exchange-correlation functional for main group chemistry. The ISI functional is based on an interpolation between the weak and strong coupling limits and includes exact-exchange as well as the G\"orling-Levy second-order energy. We have analyzed in detail the basis-set dependence of the ISI functional, its dependence on the ground-state orbitals, and the influence of the size-consistency problem. We show and explain some of the expected limitations of the ISI functional (i.e. for atomization energies), but also unexpected results, such as the good performance for the interaction energy of dispersion-bonded complexes when the ISI correlation is used as a correction to Hartree-Fock.