Abstract
The near-equilibrium potential energy surface (PES) of the ã 3B1 state of SO 2 is developed from explicitly correlated spin-unrestricted coupled cluster calculations with single, double, and perturbative triple excitations with an augmented triple-zeta correlation-consistent basis set. The lowest-lying ro-vibrational energy levels of several sulfur isotopologues have been determined using this PES. It is shown that the new ab initio PES provides a much better description of the low-lying vibrational states than a previous PES determined at the multi-reference configuration interaction level. In particular, the theory-experiment agreement for the three lowest-lying vibrational transitions is within 1-3 cm −1 .
Original language | English |
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Article number | 144303 |
Journal | Journal of Chemical Physics |
Volume | 150 |
Issue number | 14 |
DOIs | |
State | Published - Apr 14 2019 |