Computational models of the single substitutional nitrogen atom in diamond

Abstract

The single substitutional nitrogen atom in diamond is apparently a very simpledefect in a very simple elemental solid. It has been modelled by a range ofcomputational models, few of which either agree with each other, or with theexperimental data on the defect. If the computational models of less wellunderstood defects in this and more complex materials are to be reliable, weshould understand why the discrepancies arise and how they can be avoided infuture modelling. This paper presents an all-electron, augmented plane-wave(APW) density functional theory (DFT) calculation using the modern APW withlocal orbitals full potential periodic approximation. This is compared to DFT,finite cluster pseudopotential calculations and a semi-empirical Hartree–Fockmodel. Comparisons between the results of these and previous models allow us todiscuss the reliability of computational methods of this and similar defects.