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SHELX C/D/E: Difference between revisions
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The -b switch in SHELXE causes updated heavy atom positions to be written to the file name.hat (or name_i.hat). This file can be copied or renamed to the .res file (which should be saved first!) and used to recycle the heavy atoms. Versions 0.0.34 and later of the graphics program Coot (Emsley & Cowtan, Acta Cryst. D60 (2004) 2126-2132) should be able to deduce the space group name from the symmetry operators in this file, and so a very convenient way to obtain a map after running SHELXE is to start Coot, read in 'coordinates' from the .hat or _i.hat file, and then input the phases from the .phs or _i.phs files and the phases of the heavy atom substructure from the .pha or _i.pha files. It is normally necessary to increase the sigma level of the latter map (by hitting '+' several times). This procedure even works correctly when the space group has been inverted by SHELXE! <br> | The -b switch in SHELXE causes updated heavy atom positions to be written to the file name.hat (or name_i.hat). This file can be copied or renamed to the .res file (which should be saved first!) and used to recycle the heavy atoms. Versions 0.0.34 and later of the graphics program Coot (Emsley & Cowtan, Acta Cryst. D60 (2004) 2126-2132) should be able to deduce the space group name from the symmetry operators in this file, and so a very convenient way to obtain a map after running SHELXE is to start Coot, read in 'coordinates' from the .hat or _i.hat file, and then input the phases from the .phs or _i.phs files and the phases of the heavy atom substructure from the .pha or _i.pha files. It is normally necessary to increase the sigma level of the latter map (by hitting '+' several times). This procedure even works correctly when the space group has been inverted by SHELXE! <br> | ||
Good quality MAD data, a high solvent content and/or high resolution for the native data can lead to maps of high quality that can be autotraced (e.g. with wARP) immediately. The .phs files contain h, k, l, F, fom, | Good quality MAD data, a high solvent content and/or high resolution for the native data can lead to maps of high quality that can be autotraced (e.g. with wARP) immediately. The .phs files contain h, k, l, F, fom, phi and sig(F) in free format and can be read directly into Coot or converted to CCP4 .mtz format using f2mtz, e.g. for further density modification exploiting NCS using the CCP4 program Pirate. Note that if the inverted heavy atom enantiomorph is the correct one, the corresponding phases are in the *_i.phs file and SHELXE may have inverted the space group (e.g. P41 to P43), which should be taken into account when moving to other programs!<br> | ||
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== Obtaining the SHELX programs == | == Obtaining the SHELX programs == | ||
SHELXC/D/E and test data may be downloaded from the SHELX fileserver. The application form should be printed out from http://shelx.uni-ac.gwdg.de/SHELX/ This form should be completed and faxed to +49-551-392582. Downloading instructions will then be emailed to the address given on the form. The programs are free to academics but a small license fee is required for 'for-profit' use. <br> | SHELXC/D/E and test data may be downloaded from the SHELX fileserver. The application form should be printed out from http://shelx.uni-ac.gwdg.de/SHELX/ This form should be completed and faxed to +49-551-392582. Downloading instructions will then be emailed to the address given on the form, so please write the email address CLEARLY. The programs are free to academics but a small license fee is required for 'for-profit' use. <br> | ||
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If these programs prove useful, you may wish to cite (and read!):<br> | If these programs prove useful, you may wish to cite (and read!):<br> | ||
Sheldrick, G.M. (2008). "A short history of SHELX", Acta Crystallogr. D64, 112-122 [Standard reference for all SHELX... programs].<br> | |||
Sheldrick, G.M., Hauptman, H.A., Weeks, C.M., Miller, R. & Usón, I. (2001). "Ab initio phasing". In International Tables for Crystallography, Vol. F, Eds. Rossmann, M.G. & Arnold, E., IUCr and Kluwer Academic Publishers, Dordrecht pp. 333-351 | Sheldrick, G.M. (2008). "A short history of SHELX", ''Acta Crystallogr''. '''D64''', 112-122 [''Standard reference for all SHELX... programs''].<br> | ||
Schneider, T.R. & Sheldrick, G.M. (2002). "Substructure Solution with SHELXD", Acta Crystallogr. D58 1772-1779 | |||
Sheldrick, G.M. (2002), "Macromolecular phasing with SHELXE", Z. Kristallogr. 217, 644-650 | Sheldrick, G.M., Hauptman, H.A., Weeks, C.M., Miller, R. & Usón, I. (2001). "Ab initio phasing". In ''International Tables for Crystallography'', Vol. F, Eds. Rossmann, M.G. & Arnold, E., IUCr and Kluwer Academic Publishers, Dordrecht pp. 333-351 [''Full background to the dual-space recycling used in SHELXD''].<br> | ||
Schneider, T.R. & Sheldrick, G.M. (2002). "Substructure Solution with SHELXD", ''Acta Crystallogr''. '''D58''', 1772-1779 [''Heavy atom location with SHELXD''].<br> | |||
Sheldrick, G.M. (2002), "Macromolecular phasing with SHELXE", ''Z. Kristallogr''. '''217''', 644-650 [''The definitive reference for SHELXE, usually cited wrongly''].<br> | |||
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See also the SHELX homepage at: http://shelx.uni-ac.gwdg.de | |||
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