JOURNAL OF MOLECULAR SPECTROSCOPY 183, 263–272 (1997) ARTICLE NO. MS977295 Fourier Transform Emission Spectroscopy of ScH and ScD:

The emission spectra of ScH and ScD have been investigated in the near infrared and visible using a Fourier transform spectrometer. The molecules were excited in a scandium hollow cathode lamp operated with neon gas and a trace of hydrogen or deuterium. Apart from the X 1S / , B 1P, C 1S / , and G 1P states reported previously [R. S. Ram and P. F. Bernath, J. Chem. Phys. 105, 2668–2674 (1996)] , four additional new singlet electronic states A 1D, D 1P, E 1D, and F 1S0 have been identified below 21 000 cm01. The rotational analysis of several vibrational bands of the D 1P–X 1S /, D 1P–A 1D, E 1D–B 1P, E 1D–A 1D, and F 1S0–B 1P transitions has been carried out and spectroscopic constants have been determined. The E 1D state of ScH was not located because of the very weak intensity of the E 1D–B 1P and E 1D– A 1D transitions. q 1997 Academic Press INTRODUCTION MRD-CI calculations on the electronic states of ScH related to the 3d 14s 2, 3d 24s 1, and 3d 14s 14p 1 configurations of the Sc atom. They have predicted the spectroscopic propertiesIn the past decade considerable progress has been made of numerous excited electronic states as well as the transitionin understanding the electronic structure of transition metal dipole moments between many of the states.hydrides, but until recently the electronic spectra of the IIIB Very recently we have reported on the analysis of severaltransition metal hydride family (ScH, YH, LaH) were not well understood. For YH (1–3) and LaH (4, 5) new a