Debye-Waller effects on x-ray near-edge spectra

We present an ad hoc method to include Debye-Waller effects in theoretical near-edge spectra that are obtained without use of real-space multiple scattering. Instead of considering the mean square fluctuations of interatomic distances in an atom-by-atom fashion, we model the fluctuations as a continuous function of distance that approaches a long-range limit. A near-edge spectrum is converted from the energy domain to the wave-vector domain and Fourier-transformed to a pseudo-real-space (PRS) domain. In the PRS domain, the real-space coordinate is the difference between any two scattering paths that a photoelectron can take to achieve a given final state. We window the real-space transform of the spectrum using overlapping triangle functions and convolve each portion with a distance-dependent Gaussian before returning to the energy domain. We will show results for simple metals and semiconductors. The fluctuations can be obtained from traditional models, molecular dynamics, extended x-ray absorption fine structure (EXAFS) data and crystallographic data.