A theory for the reliable prediction of the EPR $g$ tensor for paramagnetic defects in solids is presented. It is based on density functional theory and on the gauge including projector augmented wave approach to the calculation of all-electron magnetic response. The method is validated by comparison with existing quantum chemical and experimental data for a selection of diatomic radicals. We then perform the first prediction of EPR $g$ tensors in the solid state and find the results to be in excellent agreement with experiment for the $E_1^{\prime }$ and substitutional phosphorus defect centers in quartz.

• Received 17 September 2001

DOI:https://doi.org/10.1103/PhysRevLett.88.086403