Predicted vibration–rotation levels of H2He+ and its isotopomers

Variational bound state nuclear motion calculations are performed on a fitted [Joseph and Sathyamurthy, J. Chem. Phys. 86, 704 (1987)] ab initio surface for HeH+2. The linear 4HeH+2 molecule is predicted to have an He–H+2 stretch fundamental of 732 cm−1 with the first J=0 excited bend at 960 cm−1. This isotopomer has no bound excited states of the H+2 vibrational mode. Calculations with J=1 and J=2 predict a rotational constant of 4.0 cm−1 for this system. Results are also presented for all the isotopomers containing D and 3He. The spectrum of this molecule is a good candidate for laboratory or astrophysical observation.