We present a reciprocal-space pseudopotential scheme for calculating X-ray absorption near-edge structure (XANES) spectra. The scheme incorporates a recursive method to compute absorption cross section as a continued fraction. The continued fraction formulation of absorption is advantageous in that it permits the treatment of core-hole interaction through large supercells (hundreds of atoms). The method is compared with recently developed Bethe-Salpeter approach. The method is applied to the carbon K-edge in diamond and to the silicon and oxygen K-edges in alpha-quartz for which polarized XANES spectra were measured. Core-hole effects are investigated by varying the size of the supercell, thus leading to information similar to that obtained from cluster size analysis usually performed within multiple scattering calculations.
@article{arxiv.cond-mat/0207733,
title = {X-ray Absorption Near-Edge Structure calculations with pseudopotentials. Application to K-edge in diamond and alpha-quartz},
author = {Mathieu Taillefumier and Delphine Cabaret and Anne-Marie Flank and Francesco Mauri},
journal= {arXiv preprint arXiv:cond-mat/0207733},
year = {2009}
}