Bound and quasibound states of HeH2+ and its isotopomers

Bound and quasibound states of HeH2+ and its isotopic variants have been computed on the recently reported ab initio potential energy surface by Palmieri et al. [Mol. Phys. 98 (2000) 1835] using a time-dependent wave packet methodology. It is shown for the first time that the lowest energy bound states for HeH2+ and HeD2+ in three dimensions are doublets, with a splitting of 7.0 and 4.8 cm−1, respectively. Such a finding has profound implications for the interpretation of microwave and other spectra for the system.