On Tue, Sep 04, 2012 at 10:01:22PM -0500, Robert Hanson wrote: > I'm most interested in how to interpret the x1,x2,x3,x4,... algebra as > symmetry operations. All I did (admittedly just a guess) was to ignore > anything after x3 and make x1=x, x2=y, x3=z. (At least it reported the > correct space group as calculated from the operators!)
My hunch is that this is a reasonable first-order approach to represent the structural motif and its local symmetry. Superspace groups come in when considering the larger-scale symmetry in the crystal, where it is not strictly periodic, but can be described (or at least approximated), sometimes by superimposition of different crystal lattices, sometimes (as in the use of superspace groups) by a projection into 3-space of a lattice exhibiting symmetry in 4-dimensional space. It may be that, in practice, it's difficult to represent this visually on the scale of a few unit cells, and showing a very extended lattice with these incommensurate effects may be stretching Jmol's capacity. But I will get those articles out to you later today, Bob, and we'll seek guidance from the experts in the field too. Best wishes Brian ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Jmol-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/jmol-users
