Spin–Orbit Type Perturbations in theB(1)1Π State of ScCl: Characterization of the Interacting (1)3Σ+State

✍ Scribed by F. Taher; A. Bernard; C. Effantin; J. d'Incan; E.A. Shenyavskaya; J. Vergès

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 195 KB
• Volume: 179
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1996.0201

✦ Synopsis

An extensive study of the B(1) 1 P r X 1 S / system of 45 Sc 35 Cl and 45 Sc 37 Cl observed in high resolution spectra of the molecular thermal emission is presented. The rotational analysis reveals the presence of localized perturbations in almost all branches of bands with £ £ 5, associated with hyperfine broadening of the perturbed Q lines. These effects are interpreted as consequences of the avoided crossing between B(1) 1 P(£) and (1) 3 S / (£ / 2) levels due to spinorbit interaction. It appears possible to enter the interacting levels for both isotopomers in the same matrix representation, the energy term elements only involving equilibrium parameters of the states (isotopically scaled to 45 Sc 35 Cl). A semideperturbed model of the interacting states, taking account of the (£ Ç £ / 2) perturbations only, is first envisaged. The simultaneous fit of some 6600 line wavenumbers in 17 bands for 45 Sc 35 Cl and 7 bands for 45 Sc 37 Cl with a total standard deviation of 0.005 cm 01 makes it possible to characterize the (1) 3 S / state and precisely describe B(1) 1 P from £ Å 0 to £ Å 5. Spin-orbit interaction parameters j £,£/2 are determined. A full deperturbation is then carried out using a model describing the levels £ Å 0 to £ Å 7 of 45 Sc 35 Cl and £ Å 0 to £ Å 4 of 45 Sc 37 Cl for the two states, and taking account of all significant interactions. The following principal equilibrium molecular constants (in cm 01 ) are obtained:

-for ( 1) 3 S / , T e Å 5388.23, v e Å 367.57, v e x e Å 1.29, B e Å 0.15550, a e Å 0.00081, 10 6 D e Å 0.111; -for B(1) 1 P, T e Å 6016.09, v e Å 381.89, v e x e Å 1.37, B e Å 0.15511, a e Å 0.00079, 10 6 D e Å 0.103.

The vibration-independent spin -orbit interaction parameter is directly determined, j el Å 53.02 cm 01 .