XPREP and SHELXC use different algorithms and sometime one of them will give better results than the other. In particular for MAD data, XPREP takes the actual f' and f" values into account and can refine them if you have at least three wavelengths, whereas SHELXC uses standard values and scales them as required. XPREP does lots of other things that can be useful for experimental phasing, e.g. space group determination, merging data, twinning detection and anisotropic scaling.
George Prof. George M. Sheldrick FRS Dept. Structural Chemistry, University of Goettingen, Tammannstr. 4, D37077 Goettingen, Germany Tel. +49-551-39-3021 or -3068 Fax. +49-551-39-2582 On Wed, 13 Feb 2008, Tommi Kajander wrote: > Dear All, > > A very simple stupid question: is it worth while getting xprep > instead of shelxc to do the same job? i realize xprep does a lot of > other things, but also seem to get the idea from some places that > it does a better job than shelxc at preparing data from shelxd, or is there > any difference (getting xprep will cost some money so i would like to know > where the difference lies if there is any significant difference??) > > Thanks for advice, > Tommi > > > > > -- > Tommi Kajander, Ph.D. > Macromolecular X-ray Crystallography > Research Program in Structural Biology and Biophysics > Institute of Biotechnology > P.O. Box 65 (Street address: Viikinkaari 1, 4th floor) > University of Helsinki > FIN-00014 Helsinki, Finland > Tel. +358-9-191 58903 > Fax +358-9-191 59940 >
