Feature Requests item #3036295, was opened at 2010-07-28 17:14 Message generated for change (Comment added) made by hansonr You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=379136&aid=3036295&group_id=23629
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: None Group: None Status: Open Priority: 5 Private: No Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: Polyhedral volumes Initial Comment: For cystallographic calculations, it would be useful to compute and display the properties of polyhedra, including volumes, quadratic elongation, angle variance etc. This is done very well in VESTA and DrawXTL. As with distances and angles, it would also be useful to compute propogated errors if uncertainties on cell parameters and atomic coordinates are provided in the input file. ---------------------------------------------------------------------- >Comment By: Bob Hanson (hansonr) Date: 2010-09-01 10:12 Message: If you can define these, I could take a look. Volume would be trivial. I don't know what the others mean. ---------------------------------------------------------------------- Comment By: Nobody/Anonymous (nobody) Date: 2010-07-29 19:32 Message: Hi, not sure exactly what else you want to know. The classic reference on polyhedral distortion metrics is Robinson et al. 1971, Science 172, 567-570. Understanding P and T-induced changes on polyhedral properties is something very important in all areas of crystallography - certainly the perovskite crowd want to understand contributions to phase changes from polyhdedral tilting and distortion (bit of an old ref, but see Thomas (1989) Acta Cryst B 45, 337-344). For my own part, I want to demonstrate the relative compressibility* of different coordination polyhedra in my structures (e.g., sulfate tetrahedra are very stiff, and MgO6 octahedra are quite squashy, often more so than the bulk structure). There is an interesting paper on polyhdral compressibilities in minerals by Bob Hazen (1988), Am. J. Sci. 288A, 242-269 (www.geology.yale.edu/~ajs/1988/Wones.1988.09Hazen.pdf). As I say, both VESTA (http://www.geocities.jp/kmo_mma/crystal/en/vesta.html) and DrawXTL (http://www.ccp14.ac.uk/ccp/web-mirrors/larryfinger/~larry.finger/drawxtl/) compute polyhdral parameters, but neither propagate errors, so this may be very hard to do. *Actually, that makes me realise that it would also be useful to have a means of representing tensorial properties over a crystal structure, for example a thermal expansion tensor representation surface or an elastic stiffness tensor. This would be great to show correlations between, say, directions of greatest compressibility and some structural element. One would want to load a file with tensor components and then plot a surface (like WinTensor). Cheers ---------------------------------------------------------------------- Comment By: Bob Hanson (hansonr) Date: 2010-07-29 07:57 Message: tell me more. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=379136&aid=3036295&group_id=23629 ------------------------------------------------------------------------------ This SF.net Dev2Dev email is sponsored by: Show off your parallel programming skills. Enter the Intel(R) Threading Challenge 2010. http://p.sf.net/sfu/intel-thread-sfd _______________________________________________ Jmol-developers mailing list Jmol-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jmol-developers
