Theoretical study on spectroscopic properties of low-lying excited states of SnS molecule
The 18 Λ-S states corresponding to the first dissociation limit of SnS moleculeare calculated with multi-reference configuration interaction(MRCI)method.In the calculation,the aug-cc-pwCVQWZ-PP base with ECP28MDF pseudopotential is used for Sn atom,and the aug-cc-pwCVQZ base is used for S atom.The potential energy curves(PECs)of SnS molecule is drawn according to the calculated eigen-values.Based on the PECs,the spectroscopic constants of bound state are obtained by solving the Schrödinger equation.The calculated spectroscopic constants are in good agreement with previous experimental results.The permanent dipole moment(PDMs)of 18 Λ-S states is calculated,and its variation is discussed.In addition,the coupling matrix elements of13∏,11∑-,11△,13∑-,13△ and 1 3∑+are calculated,and the interaction between those electronic states is elucidated by analyzing the coupling matrix elements.Finally,the transition properties of 21∑+-X1∑+,11∏-X1∑+,11∏-11△,and11∏-11∑-transitionsare analyzed,including transition dipole moments(TDMs),Frank-Condon factors(FCFs)and radiative lifetimes.
SnSpotential energy curvespectroscopic constanttransition dipole moment