Energy levels and mid-infrared spectrum of Rydberg states of triatomic hydrogen

In previous studies[1] of the dissociative recombination of ${H_3^+}$, the rigid rotator approximation, and in some cases the adiabatic hyperspherical approximation as well, were adopted by calculations of the rovibrational states of $\rm{H_3^+}$. In this work, the Coriolis interaction is considered, and accurate rovibrational energy levels of $\rm{H_3^+}$ are calculated, with the aim of eventually improving the approximations presently used in recombination theory. We also use these accurate rovibrational states of $\rm{H_3^+}$ to study the energy levels and mid-infrared spectrum of nonpenetrating $\rm{H_3}$ Rydberg states. [1] V. Kokoouline and C. H. Greene, Phys. Rev. A 68, 012703 (2003).