The shapes of absorption bands due to S0→S1 transitions in photochromic molecules

The shapes of optical absorption bands of one- and two-proton subsystems of photochromic molecules are calculated by semiclassical methods. The analysis is carried out, assuming that radiation absorption is accompanied by the S-0 --> S-1 electron transition between the nondegenerate singlet states of molecules. A correlation between the band shape and the parameters of the potential is established on a quantitative level.