The R2 EPR centre and 1.685 eV absorption line in diamond

摘要: The R2 EPR centre and 1.685 eV zero-phonon line seen in the optical absorption spectrum of diamond. have been shown to correlate intensity are believed be associated with same defect. We propose that defect responsible is a highly strained vacancy, origin strain possibly being carbon interstitial. Existing stress parameters for neutral vacancy predict an energy level structure good agreement those proposed centres. Furthermore, model identifies 3T1 unperturbed (predicted theoretically but not observed previously) as located up 200 meV above 1E ground state.