Automatic structure determination from powder data with<i>EXPO2004</i>

EXPO2004 is the updated version of the EXPO program [Altomare et al. (1999). J. Appl. Cryst . 32 , 339–340]. The traditional steps of the ab initio powder solution process are performed automatically: indexing, space-group determination, decomposition of the pattern for extracting the observed structure-factor moduli, structure solution by direct methods, model refinement by Rietveld technique. Special strategies may be applied to improve both the estimates of the extracted structure-factor moduli and the quality of the structure model. In addition, the use of special procedures exploiting available supplementary information on molecular geometry can be successfully adopted. The graphical interface has also been improved.