A General and Transferable Local Hybrid Functional for Electronic Structure Theory and Many-Fermion Approaches

TL;DR

This paper introduces a new local hybrid density functional that is highly transferable and performs well across a wide range of electronic structure applications, from molecules to solids, with broad applicability to various fermions.

Contribution

A novel, first-principles constructed local hybrid functional that achieves constraint satisfaction with full exact exchange and demonstrates broad transferability and accuracy.

Findings

Excellent performance across thermochemical and spectroscopic tests

Numerically robust with small grid requirements

Generalizable to arbitrary fermions like protons

Abstract

Density functional theory has become the workhorse of quantum physics, chemistry, and materials science. Within these fields, a broad range of applications needs to be covered. These applications range from solids to molecular systems, from organic to inorganic chemistry, or even from electrons to other fermions such as protons or muons. This is emphasized by the plethora of density functional approximations that have been developed for various cases. In this work, a new local hybrid exchange-correlation density functional is constructed from first principles, promoting generality and transferability. We show that constraint satisfaction can be achieved even for admixtures with full exact exchange, without sacrificing accuracy. The performance of the new functional for electronic structure theory is assessed for thermochemical properties, excitation energies, M\"ossbauer isomer shifts, NMR spin--spin coupling constants, NMR shieldings and shifts, magnetizabilities, as well as EPR hyperfine coupling constants. Here, the new density functional shows excellent performance throughout all tests and is numerically robust only requiring small grids for converged results. Additionally, the functional can be easily generalized to arbitrary fermions as shown for electron-proton correlation energies. Therefore, we outline that density functionals generated in this way are general purpose tools for quantum mechanical studies.