SNAP-1D

SNAP-1D is a software package designed to match and analyse powder diffraction patterns utilising their full profiles. The use of the full-profile allows for more flexible and accurate identification of samples, even when data quality is low or preferred orientation effects are significant.

The software provides an easy to use interface to several powerful and novel statistical methods to rank patterns in order of their similarity to any selected sample, allowing unknowns to be quickly identified. In quantitative mode, given a mixture pattern and potential pure phase patterns, it can identify which patterns are in the mixture, and quantify their proportions quickly and easily using a non-Rietveld based approach.

SNAP-1D contains 4 components:

    1. Pattern Editor: To view, edit, pre-process individual patterns and create a database. This includes:
      • Background substraction
      • Smoothing using wavelets
      • Peak selection using Savitzky-Golay filters
    2. Full-profile Pattern Matching: To match a reference pattern with the database entries, parametric and non-parametric statistical methods based on the full measured data are used
    3. Detailed Peak Matching: With very similar patterns a detailed peak by peak comparison can be carried out
    4. Quantitative Analysis: If the reference contains a mixture of components the software identifies these and their relative proportions with error estimates and without the use of traditional Rietveld refinement

Reference

Barr, G., Dong, W. & Gilmore, C.J. (2004). J. Appl. Cryst. 37, 658-664

 

PolySNAP is developed at the University of Glasgow.

 

Chris Gilmore's webpage