ATSAS is a program suite for small-angle scattering data analysis from biological macromolecules. It includes multiplatform data manipulation and displays tools, programs for automated data processing and calculation of overall parameters, usage of high- and low-resolution models from other structural methods, algorithms to build three-dimensional models from weakly interacting oligomeric systems and complexes, and enhanced tools to analyse data from mixtures and flexible systems.


GENFIT is a software tool for analysing small-angle scattering (SAS) data from X-ray (SAXS) or neutron (SANS) experiments. It reads in a set of one-dimensional scattering curves and fits them using different kinds of models. SAS curves calculated from a model can be smeared to allow for the instrumental resolution. The user can fit the experimental data selecting one or more models from a list including more than 30 models, starting from simple asymptotic behaviours (Guinier's law, Porod's law, etc.) down to complete atomic structures. Some models, which are defined in terms of both form and structure factors, take into account the interactions between particles in solution. GENFIT is able to simultaneously fit more SAS curves via a unique model or a mixture of models. In the latter case, some specific model parameters can be shared by any selection of the experimental curves. Model parameters can be related to the experimental chemical-physical conditions (temperature, pressure, concentration, pH, etc.) by means of link functions, which can be freely defined by the user. On the other hand, GENFIT can be used to generate theoretical SAS curves from a given model and/or from the knowledge of the species in solution. It can hence be a useful instrument to find the optimum experimental conditions for a planned SAS experiment. GENFIT is written in Fortran. Versions 2.0 and higher make use of a graphical user interface (GUI) to manage input files and execute the calculations.


Materials Analysis Using Diffraction: A Rietveld extended program to perform combined analyses. It can be used to fit diffraction, fluorescence and reflectivity data using X-ray, neutron, TOF or electrons


Mosflm can process diffraction images from a wide range of detectors and produces, as output, an MTZ file of reflection indices with their intensities and standard deviations (and other parameters). This MTZ file is passed onto other programs of the CCP4 program suite (SORTMTZ, SCALA, TRUNCATE) for further data reduction.


NRS is a fitting and simulation routine for nuclear resonant scattering, based on CONUSS (s. the related catalogue entry). It can fit and simulate both spectra in the time domain and in the energy domain. The program allows for three different scattering geometries: forward scattering, grazing incidence scattering, and a combination of both. In addition, it can be used to simulate electronic and nuclear reflectivity curves.


OCEAN is a versatile package for performing first-principles calculations of core edge spectroscopy. The many-body method is based on ground-state density-functional theory (DFT) and uses the Bethe-Salpeter equation. OCEAN utilizes the programs ABINIT or QuantumESPRESSO for ground-state DFT portion of the calculations. OCEAN is capable of producing various spectra including X-ray absorption near-edge spectra (XANES), X-ray emission spectra (XES), and non-resonant inelastic X-ray scatter (NRIXS or XRS). OCEAN is the result of collaboration between the Rehr group at the University of Washington and Eric Shirley at the National Institute of Standards and Technology (USA).


PDFgetX3 is a command-line utility for converting X-ray powder diffraction data to atomic pair distribution functions (PDF) in automated batch processing. The interactive mode provides complete access to all parameters and intermediate results, as well as live-plotting feature for parameters tuning and visualization of their effects on the results. PDFgetX3 can be used either as a standalone application or as a Python library of PDF-processing functions.


The program REFTIM calculates and fits the time spectra of nuclear resonant reflectivity, delayed and prompt reflectivity curves and the corresponding conversion electron Mössbauer spectra (CEMS) for any multilayer structure containing 57Fe, 151Eu, 149Sm, 119Sn or other isotopes if they have M1 Mössbauer transition. The experimental details of the nuclear resonance scattering technique with synchrotron radiation are described in the ID18 beamline Web pages.