The electronic structure and spectrum of a model compound of a spiropyran were investigated using an all valence-electrons CNDO CI method. The π → π*electronic excitations are localized on a given half of the molecule. The photochromic process is discussed on the basis of charge densities and bond orders. © 1973.
Tinland, B., Guglielmetti, R., & Chalvett, O. (1973). A theoretical CNDO CI study of the electronic spectrum and structure of a spiropyran. Tetrahedron, 29(4), 665–667. https://doi.org/10.1016/0040-4020(73)85011-2