“Beyond-zero-sum” range-separated local hybrid functional with improved dynamical correlation

Recent work has shown that range-separated local hybrid (RSLH) functionals containing correction terms for strong correlation and delocalization errors, such as ωLH23tdE, allow a remarkable paradigm change in the context of the usual zero-sum game between delocalization and static correlation errors in the development of density functional approximations. In this work, we evaluate the modification of the dynamical correlation contribution for such strong correlation-corrected RSLHs (scRSLHs) and how it affects the performance of the large GMTKN55 database of main-group thermochemistry, kinetics, and noncovalent interactions. Replacing the B95c correlation in the previous functionals by a more flexible reoptimized B97c power-series expansion leads to substantial improvements. The ωLH25tdE scRSLH provides a GMTKN55 WTMAD-2 value of 2.64 kcal/mol in self-consistent calculations, when augmented by DFT-D4 corrections. This is the lowest for any rung 4 functional today. At the same time, ωLH25tdE retains the favorable performance for spin-restricted bond dissociation, the removal of unphysical spin contamination in certain open-shell transition-metal complexes, and the correct long-range asymptotic potential, resulting in excellent results for quasiparticle computations of ionization potentials, electron affinities, and band gaps.