Effect of chemical change on TDDFT accuracy: orbital overlap perspective of the hydrogenation of retinal

Abstract

The breakdown in TDDFT accuracy that can accompany a simple chemical change can be understood and predicted using an orbital overlap perspective. This is illustrated for the hydrogenation of retinal. Errors in charge-transfer excitation energies and oscillator strengths in the donor–acceptor product are largely eliminated using a Coulomb-attenuated functional.