The H2 state of barium hydride

Publisher Website
Google Scholar
Abstract
Using a tunable laser to excite the E2 Pi -X2 Sigma + system of the BaH molecule, the authors recorded (with the help of a Fourier transform spectrometer) and analysed the fluorescence induced in both the visible and infrared regions. This was found to correspond to the E2 Pi -X2 Sigma , E2 Pi 3/2-A2 Pi 3/2,E2 Pi -B2 Sigma + and E2 Pi 3/2-H2 Delta 5/2 transitions. So the H 2 Delta state previously identified from perturbations affecting the A 2 Pi levels is directly observed for the first time. A consistent set of effective molecular constants is derived for the Omega =5/2 component of the H state from the simultaneous reduction of the wavenumbers of 164 regular lines in the E-X (0-0) band and E-H (0-0) and (0-1) sub-bands. A noticeable Lambda -type doubling occurs in H 4 Delta 5/2 levels. The constants found are (cm-1): T5/2 =9424.79 (2) ( nu = 0) and 10 497.08 (10) ( nu =1); B5/2= 3.1189 (2) ( nu =0)and 3.0569 (6) ( nu =1); and D5/2=0.89 (1)*10-4 ( nu =0) and 0.9*10-4 ( nu =1). The energies T5/2 ( nu =0, 1) refer to the level X 2 Sigma ( nu =0, N=0).