Infra-red, electron paramagnetic resonance and x-ray photoemission spectral properties of point defects in silica from first-principle calculations

First-principle calculations based on cluster models have been performed to compute the observable electronic properties of a series of dia- and param agnetic point defects in SiO2. Vibrational modes, hyperfine coupling consta nts, and core level binding energies have been determined at the Hartree-Fo ck and gradient corrected density functional theory levels and compared wit h the experimental infra-red, electron paramagnetic resonance and X-ray pho toemission spectral features, when available. The results show the potentia l of the combined use of quantum mechanical calculations and spectroscopic measurements for the structural description of point defects in silica. (C) 1999 Elsevier Science B.V. All rights reserved.