Franck–Condon factors, transition probabilities, and radiative lifetimes for hydrogen molecules and their isotopomeres

A systematic fundamental molecular database for all isotopomeres of the hydrogen molecule (H2, D2, T2, HD, HT, DT) is calculated on the basis of the latest Born–Oppenheimer potential curves and the latest electronic dipole transition moments of hydrogen molecules. Vibrational eigenvalues, Franck–Condon factors, and vibrationally resolved transition probabilities are presented for electronic transitions in each multiplet system up to principal quantum number n = 4. Radiative lifetimes of the vibrational levels in the electronically excited states are obtained from the summation over the optically allowed transitions. In a similar manner, effective transition probabilities and effective radiative lifetimes of electronically excited states are determined assuming that only the lowest vibrational level in the ground state is populated, i.e. the data are directly applicable to molecular gases. Differences between the isotopomeres are discussed briefly.