An excited state density functional theory study of the rhodopsin chromophore

Using a recently developed scheme for performing, within density functional theory, molecular dynamics and geometry optimization for fairly large syst ems in the first excited singlet state, we have studied the structure and e nergy changes that the rhodopsin chromophore undergoes during the photoisom erization from 11-cis to all-trans. We discuss the effects df relevant part s of the protein environment close to the chromophore on the isomerization barrier;md on the chromophore structure.