Hi David No F23 has 4 alternate non-equivalent origins (i.e. invariant amplitudes, different phases):
(0, 0, 0) (1/4, 1/4, 1/4) (1/2, 1/2, 1/2) (3/4, 3/4, 3/4) You can of course have other combinations of these by adding any of the 4 F-centring translations. You can work this out from this table: http://www.ccp4.ac.uk/html/cheshirecell.html For F23 (in the list on the right, 2 lines from the bottom) you see that the Cheshire space group is I-centred (Im3m in the 1st column) and the Cheshire cell is (a/2, b/2, c/2). The lattice translation gives the origin at (1/2, 1/2, 1/2) and the combination of this with the I centring of the Cheshire SG gives the origins at (1/4, 1/4, 1/4) & (3/4, 3/4, 3/4). HTH! -- Ian > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of David Waterman > Sent: 06 August 2008 13:27 > To: [email protected] > Subject: translation of atom sites and maps > > Hi, > > I have a SAD dataset in F23 that I have solved using both SHELX (via > hkl2map) and phenix, and for my own obscure reasons I want to compare the > results. Both SHELXD and phenix.hyss find 2 sites and both pipelines go on > to produce protein-like maps. I opened the heavy atom sites in Coot and > was surprised to find that the two sets of sites were different - that is, > they were not related by crystallographic symmetry. However, after looking > a little deeper, I found the tool phenix.emma, which told me that the > sites were indeed related, by a translation of {0.25, 0.25, 0.25}. > > I must admit I'm confused about how this can be the case (I thought there > was only one choice of origin?), but I'd still like to compare the > results. I can easily edit one of the pdb files of the heavy atom sites to > cause the required translation, however in order to translate the maps for > comparison in Coot I need to do something more complicated, like rotate > all of the phases in one of the MTZ files by a various amounts. How can I > change an MTZ file to result in a real space translation of the electron > density? > > Cheers > David > Disclaimer This communication is confidential and may contain privileged information intended solely for the named addressee(s). It may not be used or disclosed except for the purpose for which it has been sent. If you are not the intended recipient you must not review, use, disclose, copy, distribute or take any action in reliance upon it. If you have received this communication in error, please notify Astex Therapeutics Ltd by emailing [EMAIL PROTECTED] and destroy all copies of the message and any attached documents. Astex Therapeutics Ltd monitors, controls and protects all its messaging traffic in compliance with its corporate email policy. The Company accepts no liability or responsibility for any onward transmission or use of emails and attachments having left the Astex Therapeutics domain. Unless expressly stated, opinions in this message are those of the individual sender and not of Astex Therapeutics Ltd. The recipient should check this email and any attachments for the presence of computer viruses. Astex Therapeutics Ltd accepts no liability for damage caused by any virus transmitted by this email. E-mail is susceptible to data corruption, interception, unauthorized amendment, and tampering, Astex Therapeutics Ltd only send and receive e-mails on the basis that the Company is not liable for any such alteration or any consequences thereof. Astex Therapeutics Ltd., Registered in England at 436 Cambridge Science Park, Cambridge CB4 0QA under number 3751674
