High-resolution spectroscopy of TaS in the visible and heat-infrared regions

The spectrum of TaS between 4000 and 20 000 cm(-1) has been recorded in emi ssion from a microwave discharge with a resolution between 0.011 and 0.025 cm(-1). Seventeen electronic transitions have been rotationally analyzed. F ifteen of these have the ground state, (2)Delta, as the lower state and two of them are transitions between excited states. The ground state has been fitted to a Hund's case (a) Hamiltonian. Effective molecular constants have been determined for the excited states, which are mainly described as Hund 's case (c). Perturbations that have been found in the excited states are d iscussed. Transitions between states that are connected neither to the grou nd state nor to any of the other 14 electronic states of this work have bee n found. No analysis is presented for these transitions, but some of their characteristic features are described. (C) 1998 Academic Press.