Do isolated interstitial nickel atoms occur in diamond? A re-examination of the electron paramagnetic resonance defects NIRIM-1 and NIRIM-2

All of the electron paramagnetic resonance (EPR) and optical data relating to some of the basic nickel-related defects in diamond have been compared, as well as previously little considered information about the effects of spin-orbit coupling and the magnitude of the crystal field. New models are pr...