Old way of Space group determination: Difference between revisions

Old way of Space group determination (view source)

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 Space group determination can be done within XDS by following these steps:
 * an initial data reduction in P1, using SPACE_GROUP_NUMBER=0 (or even omitting that line)
-* after CORRECT has thus run in P1, one may try other spacegroups by inspecting the table "DETERMINATION OF LATTICE CHARACTER AND BRAVAIS LATTICE" in [[IDXREF.LP]]. An example:
+* after CORRECT has thus run in P1, one may try other spacegroups by inspecting the table "DETERMINATION OF LATTICE CHARACTER AND BRAVAIS LATTICE" in [[IDXREF.LP]] (see the example below).
+* for each possible lattice character, starting with the one corresponding to highest symmetry, do:
+** look up space groups corresponding to lattice characters from the list ''FIXME: give name'' in [[IDXREF.LP]] (again see the example below).
+** modify SPACE_GROUP_NUMBER=<number according to that list>
+** modify or insert REIDX=<12 numbers corresponding to the lattice character, from the table>
+** modify or insert UNIT_CELL_PARAMETERS= according to table, but make them obey space group requirements
+* run XDS with JOB=CORRECT. Inspect [[CORRECT.LP]] and note R-factors, I/sigma and a and b modifiers of standard deviations
+* repeat for each possible lattice character and finally decide on space group(s)
+Example of table "DETERMINATION OF LATTICE CHARACTER AND BRAVAIS LATTICE":
    LATTICE-  BRAVAIS-   QUALITY  UNIT CELL CONSTANTS (ANGSTROEM & DEGREES)  REINDEXING CARD (CORRECT)
   CHARACTER  LATTICE     OF FIT      a      b      c   alpha  beta gamma