title: Ab initio potential energy surface and vibration-rotation energy levels of sulfur dioxide.
abstract: An accurate potential energy surface of sulfur dioxide, SO2, in its ground electronic state X∼ 1A1 has been determined from ab initio calculations using the coupled-cluster approach in conjunction with the correlation-consistent basis sets up to septuple-zeta quality. The results obtained with the conventional and explicitly correlated coupled-cluster methods are compared. The role of the core-electron correlation, higher-order valence-electron correlation, scalar relativistic, and adiabatic effects in determining the structure and dynamics of the SO2molecule is discussed. The vibration-rotation energy levels of the32SO2and34SO2isotopologues were predicted using a variational approach. It was shown that the inclusion of the aforementioned effects was mandatory to attain the "spectroscopic" accuracy. © 2017 Wiley Periodicals, Inc.
authors.affiliation: Department of Chemistry, Adam Mickiewicz University, Poznań, 61-614, Poland.
authors.forename: Jacek
authors.identifier: 0000-0003-0457-3642
authors.initials: J
authors.lastname: Koput
keywords: potential energy surface; sulfur dioxide; vibration-rotation energy levels