Projector augmented wave calculation of x-ray absorption spectra at the L sub(2,3) edges

We develop a technique based on density functional theory and the projector augmented wave method in order to obtain the x-ray absorption cross section at a general edge, both in the electric dipole and quadrupole approximations. The method is a generalization of Taillefumier et al., [Phys. Rev. B 6...

Full description

Saved in:
Bibliographic Details
Published in:Physical review. B, Condensed matter and materials physics Condensed matter and materials physics, 2013-05, Vol.87 (20)
Main Authors: Bunau, Oana, Calandra, Matteo
Format: Article
Language:English
Subjects:
ABSORPTION
Absorption cross sections
Angular momentum
Channels
Condensed matter
Copper
CUPRITE
MAGNETIC FIELD
MATHEMATICAL ANALYSIS
Mathematical models
Projectors
X RAYS
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We develop a technique based on density functional theory and the projector augmented wave method in order to obtain the x-ray absorption cross section at a general edge, both in the electric dipole and quadrupole approximations. The method is a generalization of Taillefumier et al., [Phys. Rev. B 66, 195107 (2002) (http://dx.doi.org/10.1103/PhysRevB.66.195107)]. We apply the method to the calculation of the Cu L sub(2,3) edges in fcc copper and cuprite (Cu sub(2) O), and to the S L sub(2,3) edges in molybdenite (2H-MoS sub(2)). The role of core-hole effects, modeled in a supercell approach, as well as the decomposition of the spectrum into different angular momentum channels are studied in detail. In copper we find that the best agreement with experimental data is obtained when core-hole effects are neglected. On the contrary, core-hole effects need to be included both in Cu sub(2) O and 2H-MoS sub(2). Finally we show that a non-negligible component of S L sub(2,3) edges in 2H-MoS sub(2) involves transition to states with s character at all energy scales. The inclusion of this angular momentum channel is mandatory to correctly describe the angular dependence of the measured spectra. We believe that transitions to s character states are quantitatively significant at the L sub(2,3) edges of third row elements from Al to Ar.
ISSN:1098-0121
1550-235X