  Laser-induced fluorescence excitation spectrum of NiS in the wavelength range
of 450 - 560 nm has been recorded and analyzed. Thirty-five vibronic transition
bands have been observed, 29 of which are reported for the first time.
Rotational analyses indicated that all the observed bands can be attributable
to the [Omega = 0] - X^3 Sigma^- transitions of ^58 NiS (and ^60 NiS).
Twenty-five bands have been suggested to be grouped into four vibrational
progressions. Furthermore, through dispersed fluorescence measurements we
directly obtained the energies for the ground-state vibrational levels up to v"
= 6 as well as the vibrational frequency and the anharmonicity constant for the
ground state of ^58 NiS.
