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X-ray Absorption Near-Edge Structure calculations with pseudopotentials. Application to K-edge in diamond and alpha-quartz

Mathieu Taillefumier·Delphine Cabaret·Anne-Marie Flank·Francesco Mauri
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Abstract

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.

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Mathieu Taillefumier, Delphine Cabaret, Anne-Marie Flank, Francesco Mauri. 2002-07-31. X-ray Absorption Near-Edge Structure calculations with pseudopotentials. Application to K-edge in diamond and alpha-quartz. https://doi.org/10.1103/physrevb.66.195107

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