Figure 1

(a) Photoisomerization of diarylethene. (b) Reaction coordinate of ring opening/closing reaction. (c) The population transition path consists of radiative and non-radiative processes. Excitation (➖) and spontaneous decay (─·─) indicate radiative transition. Vibrational relaxation (─ ─ ─ ─) corresponds to non-radiative process. Each molecular orbital transition (HOMO → LUMO, isovalue: 0.02) corresponds to the most significant contribution for the excitation (ground- to first excited state) which is obtained from TDDFT calculation.