Evaluation of Local Hybrid Functionals for Electric Properties: Dipole Moments and Static and Dynamic Polarizabilities

Abstract

Local hybrid functionals are a class of exchange-correlation functionals that feature a real-space dependent admixture of exact (Hartree--Fock like) exchange governed by a local mixing function. Recently we reported the LH20t functional with wide chemical applicability and excellent performance for the GMTKN55 main-group energetics test suite (M.\ Haasler \emph{et al.}, \textit{J.\ Chem.\ Theory Comput.}\ \textbf{2020}, DOI: 10.1021/acs.jctc.0c00498). Here, we present a systematic evaluation of earlier and recent local hybrid functionals for large test sets of dipole moments and static polarizabilities, and for a smaller set of dynamic polarizabilities for heterocycles. Comparisons with coupled-cluster benchmark data show robust performance of all investigated local hybrids for dipole moments and polarizabilities. The two best local hybrids are the new LH20t and LH14t-calPBE. LH20t gives a percentage relative mean-square deviation of 5.87\% for the dipole-moment test set and of 4.30\% for static polarizabilities. This is only slightly inferior to the currently best performances among rung 4 functionals. Most notably, no large outliers are observed, in contrast to some other hyper-GGA functionals. This shows that the currently most highly parameterized (nine-parameter) LH20t clearly produces not only good energetics but also accurate electron densities and electric-field response. The influences of various aspects of local hybrids are examined, in order to aid in the further development of this class of functionals.