DFT2FEFFIT: a density-functional-theory-based structural toolkit to analyze EXAFS spectra

Abstract

This article presents a Python-based program, DFT2FEFFIT, to regress theoretical extended X-ray absorption fine structure (EXAFS) spectra calculated from density functional theory structure models against experimental EXAFS spectra. To showcase its application, Ce-doped fluorapatite [Ca₁₀(PO₄)₆F₂] is revisited as a representative of a material difficult to analyze by conventional multi-shell least-squares fitting of EXAFS spectra. The software is open source and publicly available.

Keywords: DFT; EXAFS; FEFF software; apatite; cerium; density functional theory; rare earth elements.