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--- adps_with_symmetry_constraints [2024/01/31 11:16] – johnsoevans
+++ adps_with_symmetry_constraints [2024/02/10 07:58] (current) – external edit 127.0.0.1
@@ Line 6: / Line 6: @@
 In all other versions of Topas, use the keyword "adps" to get Topas to insert the correct, symmetry-constrained values.
-The macros below correspond to Table 4.1 in [1], which refers to Table 4.2, which gives the necessary restrictions for each Wyckoff site in each spacegroup. I'm assuming that a general position in any space group has no constraints on the ADP values. [Note this table may have an error in space group 227 for Wyckoff site f, check against international tables - John]
+The macros below correspond to Table 4.1 in [1], which refers to Table 4.2, which gives the necessary restrictions for each Wyckoff site in each spacegroup. I'm assuming that a general position in any space group has no constraints on the ADP values.
 The U12, U13, U23 values in the tables are listed as 2*U12, 2*U13, 2*U23, so I think this means that they should be divided by two. But I think this should only be an issue in nos 13-16, where there is a constraint between U22 and U12.
+Note added by John:
+Be careful in space group 227 if you're using the Willis table.  It's missing one "18" in the list.  This means that the constraints for Wyckoff sites f onwards are displace one column to the left.  It should read "17 17 18 18 18 9 6 10".
+The Willis table is {{ :willis_adps.pdf |here}}.  You should always check carefully against (e.g. international tables) when you don't use TOPAS to generate adps.  A program like VESTA will also warn you if they are incorrect.  There is a small number of space-group/Wyckoff site combinations where TOPAS crashes when generating adps so this is sometimes needed.