Experimental [CLC][ITAL]f[/ITAL][/CLC]-Value and Isotopic Structure for the N[CLC]i[/CLC] [CSC]i[/CSC] Line Blended with [O [CSC]i[/CSC]] at 6300 Å

We have measured the oscillator strength of the Ni i line at 6300.34 A , which is known to be blended with the forbidden line [O i] l6300 used for the determination of the oxygen abundance in cool stars. We also give wavelengths of the two isotopic line components of 58 Ni and 60 Ni derived from the asymmetric laboratory line profile. These two line components of Ni i have to be considered when calculating a line profile of the 6300 A feature observed in stellar and solar spectra. We also discuss the labeling of the energy levels involved in the Ni i line since level mixing makes the theoretical predictions uncertain.