An ab initio potential energy surface and vibrational energy levels of HXeI

A three-dimensional potential energy surface of the electronic ground state HXeI is constructed from more than 4200 ab initio points at the internally contracted multi-reference configuration interaction with the Davidson correction (icMRCI + Q) level employing large basis sets. The calculations indicate that the linear HXeI molecule is metastable with a barrier of 0.365 eV in the atomization (HXeI → H + Xe + I) channel and a barrier of 1.306 eV in the dissociation (HXeI → HI + Xe) channel. Low-lying vibrational energy levels of both HXeI and DXeI are calculated on the three-dimensional potential energy surface using the Lanczos algorithm, and found to be in good agreement with known experimental band origins.