A Simulated Annealing Approach for Crystal Structure Solution from Powder Diffraction Data

Abstract

We discuss fundamentals and applications of the program “Powder Solve” that has been developed to solve crystal structures directly from powder diffraction data. The program uses a combination of simulated annealing and rigid-body Rietveld refinement techniques to find the trial structure giving maximal agreement between calculated and experimental powder diffraction data (assessed using the profile R-factor Rwp). Two examples are highlighted to demonstrate the application of Powder Solve for molecular crystals defined by up to 18 variable degrees of freedom.