Elucidation of optical switching of single guest molecules in terrylene/p-terphenyl mixed crystals

An empirical molecular model is used to explore the ground-state potential energy surface of a mixed crystal in which reversible, reproducible, photo-induced frequency jumps of single molecules were recently reported. In the model, which accounts for many observed features of terrylene in p-terphenyl, optical switching of the guest transition frequency corresponds to relaxation of host molecules in the second solvation shell.