An ab initio calculation of the dipole moment surfaces and the vibrational transition moments of the H2Te molecule

The present work reports an ab initio MRD-Cl calculation of the dipole moment surfaces for the electronic ground state of the H2Te molecule. Using the ab initio results, we calculate the vibrational transition moments, and we stimulate the far-infrared spectrum of H2Te by means of the MORBID program system. We obtain the equilibrium value of the dipole moment from the ab initio calculation as 0.377 Debye based on our initial theoretical treatment which was employed over a wide range of molecular geometrics. However, the use of an improved AO basis at the equilibrium geometry of H2Te lowers this results to 0.298 Debye. The comparison of our simulated far-infrared spectrum with the experimental spectrum suggests that this value is too large, and that the correct value is certainly larger than 0.19 Debye and very probably smaller than 0.26 Debye. From the ab initio data, we predict many vibrational transition moments for H2Te, D2Te, and HDTe. We hope that these results will be of assistance in the interpretation of the rotation-vibration spectrum of these molecules. (C) 1997 Academic Press, Inc.