A theoretical-spectroscopy, ab initio-based study of the electronic ground state of 121SbH3

For the stibine isotopologue SbH3121, we report improved theoretical calculations of the vibrational energies below 8000 cm−1 and simulations of the rovibrational spectrum in the 0-8000 cm−1 region. The calculations are based on a refined ab initio potential energy surface and on a new dipole moment surface obtained at the coupled cluster CCSD(T) level. The theoretical results are compared with the available experimental data in order to validate the ab initio surfaces and the TROVE computational method [Yurchenko SN, Thiel W, Jensen P. J Mol Spectrosc 2007;245:126-40] for calculating rovibrational energies and simulating rovibrational spectra of arbitrary molecules in isolated electronic states. A number of predicted vibrational energies of SbH3121 are provided in order to stimulate new experimental investigations of stibine. The local-mode character of the vibrations in stibine is demonstrated through an analysis of the results in terms of local-mode theory.