Ab initio calculations on the ground and excited electronic states of ScH molecule

Ab initio potential energy curves and transition dipole moments have been calculated for the X1Σ+, A1Δ, B1Π, C1Σ+, D1Π, E1Δ, F1Σ−, G1Π, 31Δ, 21Σ−, 41Δ, 41Π, 31Σ+ and 51Π states of scandium hydride, ScH, using the multi-reference configuration interaction method with large active space and basis sets. Calculations were performed at 50 internuclear distances. Potential energies, dipole moment and transition dipole moments have been computed from 1.0 Å to 20.0 Å. In order to compute Einstein A coefficients and spectroscopic constants, potential energy values and transition dipole moments of the ground and singlet excited states were used in program LEVEL. Einstein A coefficients, Franck-Condon factors and average lifetimes for vibrational levels of excited electronic states for the B1Π - X1Σ+, C1Σ+ - X1Σ+ , D1Π – X1Σ+ and G1Π – X1Σ+ band systems of ScH were calculated. We obtained a lifetime of 90 μs for the v′ = 0 level of the B1Π state and 137 ns for the v′ = 0 level of the C1Σ+ state of ScH. The spectroscopic parameters of the bound states were determined, which agree well with available experimental results.