Differences

This shows you the differences between two versions of the page.

@@ Line 1: / Line 1: @@
+====== Stacking Faults ======
+Topas v5 and v6 include a number of options for including stacking faults using a supercell approach.  In particular, v6 contains significant speed ups.  These include use of an intelligeng peak buffer; a process which allow the rapid averaging of hundreds of individual supercells; a smoothing technique to approximate supercells 10-20 times larger than those used; and efficient algorithms for generating stacking sequences.  There's a speed gain of several thousand over a conventional Rietveld approach.  The language for describing supercells is deliberately similar to that used in DIFFaX.
+Details are in the manual and in the the publications below.  There's also an [[http://community.dur.ac.uk/john.evans/topas_workshop/tutorial_stacking_faults.htm|online tutorial]] featuring some of the examples from the Topas User Meeting in Bari.  It is available [[http://community.dur.ac.uk/john.evans/topas_workshop/tutorial_stacking_faults.htm|here]].  You'll be able to get simple one or two parameter fits to data like:
+{{:stacking.jpg?direct&400|}}
+You might also be interested in the following papers:
+Coelho, Alan A., J. S. O. Evans, and J. W. Lewis. "Averaging the intensity of many-layered structures for accurate stacking-fault analysis using Rietveld refinement." Journal of Applied Crystallography 49, no. 5 (2016): 1740-1749. [[http://dx.doi.org/10.1107/S1600576716013066|doi]]
+Ainsworth, Chris M., James W. Lewis, Chun-Hai Wang, Alan A. Coelho, Hannah E. Johnston, Helen EA Brand, and John SO Evans. "3D Transition Metal Ordering and Rietveld Stacking Fault Quantification in the New Oxychalcogenides La2O2Cu2–4 x Cd2 x Se2." Chemistry of Materials 28, no. 9 (2016): 3184-3195.[[http://pubs.acs.org/doi/abs/10.1021/acs.chemmater.6b00924|Link]]
+Bette, Sebastian, Robert E. Dinnebier, and Daniela Freyer. "Structure solution and refinement of stacking-faulted NiCl (OH)." Journal of Applied Crystallography 48, no. 6 (2015).[[http://scripts.iucr.org/cgi-bin/paper?po5043|Link]]