The purpose of the program is to find a structural model of a material (hopefully the right one) which agrees with the available EXAFS spectra.
In order to evaluate a structure, a model must first be defined in terms of one or more clusters of atoms, weighted according to the average composition of the material. Clusters may represent different atomic sites in a single phase, or multiple phases. A full description of each cluster requires :
- the radial or cartesian coordinates of scattering atoms about each absorbing atom for which spectra are available
- a pair distribution function for each symmetrically unique excited-atom/scattering atom pair
- the point group of each cluster
The parameters used to define the model may be refined until optimum agreement with the XAFS data is obtained.
Refinement may use additional data to that given by EXAFS spectra, for example distance and angle restraints using bond distances obtained by other techniques.
- Norman Binsted
- Contact Norman Binsted
Norman Binsted -- <SPAM SUPPRESSION n DOT binsted AT ntlworld DOT com>
EXCURV98: CCLRC Daresbury Laboratory computer program, Binsted N. (1998)