The influence of non-adiabaticity on the nuclear motion in the H3+ molecule

The rovibrational spectrum of H3+ has been analyzed by taking into account that non-adiabatic couplings can be simulated by using atomic masses for vibrational and nuclear masses for rotational motion. This results in computed transition frequencies that reproduce experiment in most cases by a factor of 10 better than the original results including only adiabatic corrections. The deviation from experiment is in the range of a few hundredths of a wavenumber.