Pat, Thank you for spotting this. It was a casualty of enabling Jmol to read Hall symbols, and it is fixed.
For the record: Originally I implemented LATT parameters as one might expect, applying the appropriate translations and/or inversion to the supplied SYMM operators, but not as full-fledged operators themselves. When I was in the UK in August I got the opportunity to meet Peter and Judith Murray-Rust, and they proceeded to explain to me how Hall symbols work and why they are so valuable. I am totally sold on this system. The outcome of that discussion was that Jmol can now read Hall symbols and construct the full set of symmetry operators from them, without need for LATT/SYMM. As part of that upgrade I consolidated all the symmetry-handling business into Hall formalism. It is interesting (I think) that any of the lattice translation/inversion designations can be considered simply as the inclusion of a set of additional Hall rotation-translation terms. So, we have: 1 ,"P", "primitive", "" 2 ,"I", "body-centered", " 1n" 3 ,"R", "rhombohedral", " 1r 1r" 4 ,"F", "face-centered", " 1ab 1bc 1ac" 5 ,"A", "A-centered", " 1bc" 6 ,"B", "B-centered", " 1ac" 7 ,"C", "C-centered", " 1ab" 8 ,"S", "rhombohedral(S)", " 1s 1s" 9 ,"T", "rhombohedral(T)", " 1t 1t" With inversion being added in as a "-1" Hall rotation. (Note that 1r, 1s, and 1t are just internal Jmol constructs -- I don't think they are described in any actual Hall description. But, if there is ever an opportunity to develop this further perhaps this can be taken as a suggestion....) Alas, I forgot to bring this formalism back into the simple RES file reader and inadvertently left the Shelx reader ignoring the LATT parameter. But it should be working correctly now. Pat, I'd appreciate it if you could give the next-released jar files a thorough review in this area in order to confirm that they are working appropriately. You probably have a good set of test files you could run this on. P.J. Carroll wrote: >When Jmol (version 11) reads SHELXL .res files, it apparently does >not correctly produce all of the symmetry operations. The center of >symmetry operation in centrosymmetric space groups is not in >operation. For example, in space group P21/c, the SHELXL file lists : > > LATT 1 > SYMM -X, .50+Y, .50-Z > >Thus, there should be four symmetry operations: > > X, Y, Z (this position is ALWAYS present!) > -X, -Y, -Z (this is produced by the LATT 1 >instruction - when LATT is > positive, a center of symmetry is present) > -X, .50+Y, .50-Z (from the SYMM line) > X, -.50-Y, -.50+Z (by the action of the >LATT 1 instruction) > >I think the action of the LATT 1 instruction is not being taken into account. > >Pat Carroll >Chem Dept >U of Penn > > > >------------------------------------------------------------------------- >Take Surveys. Earn Cash. Influence the Future of IT >Join SourceForge.net's Techsay panel and you'll get the chance to share your >opinions on IT & business topics through brief surveys -- and earn cash >http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV >_______________________________________________ >Jmol-users mailing list >[email protected] >https://lists.sourceforge.net/lists/listinfo/jmol-users > > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Jmol-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/jmol-users
