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Old way of Space group determination: Difference between revisions
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Old way of Space group determination (view source)
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Space group determination can be done within XDS by following these steps: | 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) | * 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]]. | * 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) | LATTICE- BRAVAIS- QUALITY UNIT CELL CONSTANTS (ANGSTROEM & DEGREES) REINDEXING CARD (CORRECT) | ||
CHARACTER LATTICE OF FIT a b c alpha beta gamma | CHARACTER LATTICE OF FIT a b c alpha beta gamma | ||