Semiclassical approach to the Rydberg emission spectra of H3 and its isotopomers

We investigate the optical emission spectra of Rydberg-excited H3 and its isotopomers semiclassically in the framework of the reflection principle. The semiclassical spectra are also obtained with the approximation of a locally linear potential energy surface where the contribution from the breathing and the Jahn–Teller (JT) active modes are separable. While the JT mode brings out the energy splitting in the bimodal emission profiles, the breathing mode smears out their overall structure. Despite some severe limitations of the semiclassical results, the energy splitting is reproduced well. This enables us to establish a simple kinematic scaling of this quantity for different isotopomers.