Optical emission spectra of Rydberg-excited ${\mathrm{H}}_3$, ${\mathrm{D}}_3$, ${\mathrm{H}}_2\mathrm{D}$, and ${\mathrm{D}}_2\mathrm{H}$, in the range 200–400 nm, are investigated theoretically and compared with the experimental findings of Bruckmeier et al. [Phys. Rev. Lett. 72, 2550 (1994)]. The time-dependent wave packet method combined with the vibronic coupling theory for ( $E\times \epsilon$) Jahn-Teller systems is utilized in order to calculate the corresponding Franck-Condon emission profiles from the upper $n=3\mathrm{}$ electronic state to the degenerate $\left(2p\right){1E}^{\prime }$ ground electronic manifold of those species. We obtain bimodal spectra with two maxima $9600{\mathrm{cm}}^{-1\mathrm{}}$ apart in good agreement with the experimental result.

• Received 8 April 1998

DOI:https://doi.org/10.1103/PhysRevLett.81.3116