Rydberg states of triatomic hydrogen and deuterium.

The triatomic hydrogen ion (H3(+)) has spurred tremendous interest in astrophysics in recent decades, and Rydberg states of H3 have also maintained an important role for understanding H3(+) experiments. In a previous study (J. Chem. Phys. 2010, 133, 234302), radiative transitions between neutral H3 Rydberg states were calculated at wavelengths near 7 μm and could be compared with mid-infrared laser lines observed in hydrogen/rare gas discharges. The present study extends the investigation to wavelengths near 10–13 μm. Rydberg states of D3 are also treated.