Experimental f-Value and Isotopic Structure for the Ni I Line Blended with [O I] at 6300 Å

We have measured the oscillator strength of the Ni I line at 6300.34Å, which is known to be blended with the forbidden line [O I]lambda6300 used for the determination of the oxygen abundance in coolstars. We also give wavelengths of the two isotopic line components of<SUP>58</SUP>Ni and <SUP>60</SUP>Ni derived from the asymmetriclaboratory line profile. These two line components of Ni I have to beconsidered when calculating a line profile of the 6300 Å featureobserved in stellar and solar spectra. We also discuss the labeling ofthe energy levels involved in the Ni I line since level mixing makes thetheoretical predictions uncertain.