Density functionals with asymptotic-potential corrections are required for the simulation of spectroscopic properties of materials

TL;DR

This paper demonstrates that incorporating asymptotic-potential corrections in density functionals significantly enhances the accuracy of spectroscopic property simulations across molecules, materials, and defects, suggesting a shift from standard functionals like HSE06 to corrected alternatives.

Contribution

It introduces the importance of asymptotic-potential corrections in density functionals for better spectroscopic property predictions and advocates replacing HSE06 with the asymptotically corrected CAM-B3LYP functional.

Findings

Asymptotic corrections improve charge-transfer excited state calculations.

CAM-B3LYP outperforms HSE06 in materials spectroscopy simulations.

Defects in 2D materials can be effectively modeled using corrected functionals.

Abstract

Five effects of correction of the asymptotic potential error in density functionals are identified that significantly improve calculated properties of molecular excited states involving charge-transfer character. Newly developed materials-science computational methods are used to demonstrate how these effects manifest in materials spectroscopy. Connection is made considering chlorophyll-a as a paradigm for molecular spectroscopy, 22 iconic materials as paradigms for 3D materials spectroscopy, and the VN- defect in hexagonal boron nitride as an example of the spectroscopy of defects in 2D materials pertaining to nanophotonics. Defects can equally be thought of as being "molecular" and "materials" in nature and hence bridge the realms of molecular and materials spectroscopies. It is concluded that the density functional HSE06, currently considered as the standard for accurate calculations of materials spectroscopy, should be replaced, in most instances, by the computationally similar but asymptotically corrected CAM-B3LYP functional, with some specific functionals for materials use only providing further improvements.