Abstract
The chemical shifts of the radiation line from Al, Si, and Ge ions between their elemental and oxide forms are calculated within the framework of density functional theory using ultrasoft pseudopotentials. It is demonstrated that this theoretical approach yields quantitatively accurate results for the systems investigated, provided that relaxations of the valence electrons upon the core-hole transition are properly accounted for. Therefore, such calculations provide a powerful tool for identification of impurity states based on x-ray fluorescence data. Results for an Al impurity implanted in silica are found to be in excellent agreement with experimental data, providing support for the proposed atomic geometry.
- Received 20 December 2000
DOI:https://doi.org/10.1103/PhysRevB.63.193102
©2001 American Physical Society