Laser-induced fluorescence and Fourier transform spectroscopy of the [21.9](2)Delta(5/2)-X-2 Pi(3/2) (21 910 cm(-1)) and the [21.9](2)Delta(5/2)-[.16](2)Delta(5/2) (21 750 cm(-1)) transitions of NiCl

The visible spectrum of NiCl consists of a large number of bands. Laser-ind uced fluorescence experiments have shown that two intense transitions (21 9 10 and 21 750 cm(-1)) share a common [21.9](2)Delta(5/2), upper electronic state. High-resolution Fourier transform spectroscopy has allowed the rotat ional analysis of the (0-0), (1-0), and (0-1) bands of the [21.9](2)Delta(5 /2)-[0.16](2)Delta(5/2) transition and the (0-0) band of the [21.9](2)Delta (5/2)-X(2)Pi(3/2) transition. No fluorescence to a state lower in energy th an the X(2)Pi(3/2) state was observed in our experiments. We believe that w e have identified the (2)Pi(3/2) spin-orbit component of the X(2)Pi(i) grou nd state and the (2)Delta(5/2) spin-orbit component of the first A(2)Delta( i) electronic state. (C) 2000 Academic Press.