SIXpack: a graphical user interface for XAS analysis using IFEFFIT

SIXPack (Sam's Interface for XAS analysis Package), a graphical user interface that allows users simple manipulation and analysis of data, is presented. The modules of SIXPack allow users to: (1) load, calibrate, and average raw data files; (2) perform background subtractions; (3) perform principal component analysis and target transforms; (4) perform least squares fitting of data to standards and functions; (5) perform EXAFS fitting to FEFF phase and amplitude files; (6) create single scattering FEFF phase and amplitude files using a periodic table interface. Novel features of the program allow for the fitted correction of XANES spectra due to self-absorption effects in unknown matrices, which is particularly useful for analysis of geochemical and environmental systems. The core of the XAS analysis routine uses IFEFFIT. SIXPack is developed in Python, is installable across many operating systems and platforms, and is freely available with an Open Source license.