A self-consistent, real space multiple-scattering (RSMS) approach for calculations of x-ray absorption near edge structure (XANES) is presented and implemented in an ab initio code applicable to arbitrary aperiodic or periodic systems. This approach yields a quantitative interpretation of XANES based on simultaneous, self-consistent field (SCF) calculations of local electronic structure and x-ray absorption spectra, which include full multiple scattering from atoms within a small cluster and the contributions of high order MS from scatterers outside that cluster. In addition the code includes a SCF estimate of the Fermi energy and an account of orbital occupance and charge transfer. We also present a qualitative, scattering-theoretic interpretation of XANES. Sample applications are presented for cubic BN, UF[d6], Pu hydrates, and distorted PbTiO[d3]. Limitations and various extensions are also discussed. PACS numbers: 71.10+x 79.60.-1 78.79.Dm.
Citation: Physical Review B (Condensed Matter and Materials Physics)
Pub Type: Journals
density of states, full multiple scattering, self consistent field, XAFS, XANES