Potential energy curves and spectroscopic properties of SnO (X1Σ+, a3Π and A1Π) molecule

Potential energy curves (PECs) for the ground state and the second excited state (a(3)Pi and A(1)Pi) of SnO molecule are calculated by using the multi-reference configuration interaction method (MRCI) and also considering Davidson correction' multi-reference configuration interaction method with aug-cc-pvTZ basis for O atom, aug-cc-pvTZ- PP basis for Sn atom, respectively. On the basis of the PECs, the R-e,w(e,)w(e)x(e,)B(e),T-e and D-e are obtained. The symmetries and dissociation limits for these electronic states are determined by group theory. The results show that three electronic states are dissociated along the same channel, Sn (P-3)+ O (P-3). And then the PECs are fitted by using level program. The spectroscopic constants are determined according to fitted results, which shows that MRCI results are in good agreement with the experimental values. By solving the radial Schrodinger equation of nuclear motion, the vibration levels can be obtained, molecular constant (B v and D v) are reported for the first time at J = 0