Fixed and Refined Parameters

Fix and free parameters: occupancy, xyx, uiso

{occu, xyz, Uiso} [atoms]

Fixes the specified refinement parameter, i.e. these parameters will not be refined in subsequent refinement cycles.

  • -occu: will fix the occupancy
  • -xyz: will fix the xyz coordinates
  • -Uiso: will fix the whole ADP

>>fix occu 0.5: will set and fix the occupancy of the current selection to 0.5 >>fix xyz: will fix the x, y and z co-ordinates of the currently selected atoms (i.e. not refine them).


{occu, xyz, Uiso} [atoms]

The opposite of FIX - makes the specified parameters for the given atoms refineable. Freeing the occupancy is also available from the context menu.

mode fixu

Fixes Uiso or ADP for subsequently clicked atoms.

mode fixxyx

Fixes the coordinates for subsequently clicked atoms.

mode occu


Sets atom occupancy to the provided value for subsequently clicked atoms.