Rotational study and hyperfine effects of the (0,0) band of the B2Σ- X2Σ system of ScS

Abstract

Rotational analysis of the (0,0) band of the B 2Σ- X 2Σ transition of ScS is reported. Spectrographic illustration of a hyperfine coupling transition in the ground state is demonstrated for the first time. This enables an order of magnitude to be obtained for γ″ (∼0.003 cm −1). The results for the other constants were: X state: B″ = 0.1971 cm −1, D″ = 5 × 10 −8cm −1, 4 b = 0.23 cm −1 (equal to that for ScO within the limits of measurement uncertainty); B state: B′ = 0.1853 cm −1, D′ = 6 × 10 −8cm −1, γ′ = −0.0594 cm −1, which can be compared with p A 2Π = 0.060 cm −1. It was found that the two excited states A 2Π and B 2Σ constitute an excellent example of pure precession ( p pp = 0.058 cm −1, and this enables the vibrational levels of A 2Π to be numbered.