Hello Bram,
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
[EMAIL PROTECTED]
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: [EMAIL PROTECTED]
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
