SPECTRUM AND TERM SYSTEM OF NEUTRAL NICKEL, NI-I

Spectra of nickel, emitted from hollow cathode discharges, have been r ecorded in the region 1700-55000 angstrom (58800-1800 cm-1). Fourier t ransform spectrometers were used above 1800 angstrom, yielding very hi gh accuracy and resolution. The number of classified Ni I lines has in creased from 1071 to 1996. 289 of the lines have been resolved in 2-4 isotope components. The term system derived from the observations comp rises 286 energy levels. The term structure and the coupling condition s have been studied by means of ab initio and parametric theory.