The molecular structure, spectroscopic properties and partition functions of C3H2S isomers: An ab initio study

Abstract

The anharmonic force fields, spectroscopic constants and partition functions of three isomers of C3H2S have been studied employing B3LYP, B3PW91, M06-2X, MP2 or CCSD(T) methods with 6-311++G (2d,2p) or 6-311++G (3df,2pd) basis sets. The equilibrium geometries, energies, rotational constants, harmonic and fundamental frequencies, centrifugal distortion constants and partition functions of three isomers of C3H2S are calculated and compared with the existing data. The MP2/6-311++G (3df,2pd) results well reproduce the previous theoretical or experimental results, so we predict other spectroscopic properties of C3H2S based on the MP2/6-311++G (3df,2pd) theoretical level. The relationship between structure and spectroscopic properties for three isomers of C3H2S is also analyzed in detail. We hope that the obtained spectroscopic constants and partition functions of C3H2S isomers can provide strong support for further research of spectroscopic properties.