Electronic energy funnels in cis-trans photoisomerization of retinal protonated Schiff base

Full multiple spawning method is used in investigating the photoinduced cis-trans isomerization of all-trans retinal protonated Schiff base (RPSB). The study seeks to find out if equilibrium is a condition for directed excitation transport given an electronic funnel. RPSB is known for fast quenching of less than 500 fs which guarantees that equilibrium among the excited electronic states cannot be achieved before electronic quenching. Results show quenching and exciton transfer are two distinct events although the latter is a highly directed event.