Abstract
We develop a first-principles scheme based on the continued-fraction approach and ultrasoft pseudopotentials to calculate -edge x-ray absorption spectra in solids, allowing such calculations in transition-metal and rare-earth compounds with substantially reduced cutoffs with respect to the norm-conserving case. We validate the method by calculating Si and edges in -quartz, edge in copper and in . For the case of Si and O edges in -quartz and in copper, we obtain good agreement with experimental data. In the -edge spectra of , a material considered a real challenge for density-functional theory, we attribute all the near-edge and far-edge peaks to single-particle excitations.
- Received 4 June 2009
DOI:https://doi.org/10.1103/PhysRevB.80.075102
©2009 American Physical Society