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Re: [ccp4bb] xprep vs shelxc |
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CCP4bb navigationCCP4bb <-- 2008 <-- February 2008 <-- 13 February 2008Subject: Re: xprep vs shelxc From: Tim Gruene tg {- at -} SHELX {- dot -} UNI-AC {- dot -} GWDG {- dot -} DE Date: 2008-02-13 I never did try to receive the xprep demo version twice, there is no need to worry about your administration. I am sorry I had this false concept about Bruker's xprep policy and grateful you corrected it on the board. Working in George Sheldrick's group I never had reason to consider my idea might be wrong, of course... Sorry again to everyone for giving out false information. Tim -- Tim Gruene Institut fuer anorganische Chemie Tammannstr. 4 D-37077 Goettingen GPG Key ID = A46BEE1A On Wed, 13 Feb 2008, Bram Schierbeek wrote: > Hi Tim, > > Unfortunately your statement is not true. > > The XPREP program was written by George Sheldrick over many years and it is > proprietary software distributed by Bruker AXS. > We unbundled it from our complete SHELXTL structure solution and refinement > package, specifically also to serve macromolecular crystallography groups > such as those reading this bulletin board. > > We have a demo version, which groups can try out, academics or industrials, > which expires by the end of each year. > Anyone can request a demo version by sending an email to > demolicense@rt.bruker-axs.nl. > If all is well, you should get this demo version once and not more. If you > did get it more then once, Tim, we did not do our administration right and > you were lucky, or it may be because you have changed labs every year. > If people find the software useful they can buy a perpetual license from > Bruker AXS for a moderate price. Alternatively they can buy an X-ray > diffraction system and get the software for free. > > As far as the differences between SHELXC and XPREP: > On the SHELX website it says: > "SHELXC is much less versatile than the Bruker AXS XPREP program for > macromolecular phasing, but if you are sure of the space group and there are > no problems with the indexing or twinning and the f and f" parts of the > scattering factors do not need to be refined, SHELXC should be adequate. > SHELXC can read either HKL2000 .sca files or SHELX .hkl files." > > Xprep has many more possibilities then SHELXC: It can search for higher > symmetry in datasets, determine space groups, it has tests for merohedral > twinning, reciprocal lattice displays, unit cell transformations and can > calculate Self-Rotation functions. > > The results for anomalous phasing from XPREP look better then those from > SHELXC at first sight, but I have not done a rigorous study into this matter. > Best wishes, > > Bram > > -- > ---------------------------------------------------------------------------- > Bram Schierbeek > Application Scientist Structural Biology Solutions > Bruker AXS BV > Oostsingel 209,P.O.Box 811 > 2600 AV Delft, the Netherlands > T: +31 (0)152 152 508 > F: +31 (0)152 152 599 > E: bram.schierbeek@bruker-axs.nl > W: www.bruker-axs.com > ---------------------------------------------------------------------------- > > > > Tim Gruene wrote: >> xprep is free to academics. Since your signature says you work at the >> University of Helsinki, you would only need to send an informal email to >> bruker (you could try their contact form >> http://www.bruker-axs.com/contact.html?&L=http%3A%2F%2Fhome.arcor.de%2Fjohnwayne92%2Finc.php >> ) in order to receive a binary. You do have to repeat this every year, but >> I think this is a bearable burden. >> >> As far as the differences between shelxc and xprep are concerned: shelxc is >> meant to be a non-interactive basic version of xprep so that it could be >> called from other programs. It's data preparation should be the same as in >> xprep and if it really did worse than xprep, I am sure that the improvement >> from xprep would find its way into shelxc in very little time. >> >> We use hkl2map (from Thomas Schneider) routinely for phasing purposes, and >> since hkl2map calls shelxc rather than xprep, I cannot confirm that xprep >> prepares the data in a better way than shelxc. >> >> Sincerely, Tim >> >> -- >> Tim Gruene >> Institut fuer anorganische Chemie >> Tammannstr. 4 >> D-37077 Goettingen >> >> GPG Key ID = A46BEE1A >> >> >> 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 >>> > CCP4bb navigationCCP4bb <-- 2008 <-- February 2008 <-- 13 February 2008 |
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