Tutorial(First Steps): Difference between revisions
 New page: = A beginner's walk-through to XDS =  ''This page is under development. If you think it might be useful to you and worth completing faster, why not simply bother the author by sending him ...  | 
				No edit summary  | 
				||
| Line 34: | Line 34: | ||
This is it to start. type <pre>#> xds_par </pre> to run xds and wait until it's finished.  | This is it to start. type <pre>#> xds_par </pre> to run xds and wait until it's finished.  | ||
== Indexing Fails ==  | |||
If the detector origin is too far from the image centre, IDXREF is going to stop with the error message  | |||
 !!! ERROR !!! SOLUTION IS INACCURATE  | |||
Do the following:  | |||
<source lang=fortran>  | |||
# In IDXREF.LP, find the table '''INDEXING OF OBSERVED SPOTS IN SPACE GROUP'''  | |||
 ***** INDEXING OF OBSERVED SPOTS IN SPACE GROUP #   1 *****  | |||
   16196 OUT OF   76452 SPOTS INDEXED.  | |||
       0 REJECTED REFLECTIONS (REASON: OVERLAP)  | |||
   60256 REJECTED REFLECTIONS (REASON: TOO FAR FROM IDEAL POSITION)  | |||
 EXPECTED ERROR IN SPINDLE  POSITION     2.398 DEGREES  | |||
 EXPECTED ERROR IN DETECTOR POSITION      1.72 PIXELS  | |||
</source>  | |||
Unless really hardly any reflections could be indexed (second line in the table), scroll a few lines up and copy the refined values for the beam origin  | |||
 DETECTOR ORIGIN (PIXELS) AT                     1514.16   1537.27  | |||
as improved ORGX and ORGY to [[XDS.INP]] and try indexing again.  | |||
XDS is quite robust and in many cases this approach works  | |||
# Check the refined detector distance  | |||
 DETECTOR ORIGIN (PIXELS) AT                     1514.16   1537.27  | |||
 CRYSTAL TO DETECTOR DISTANCE (mm)       422.92      | |||
If it deviates by more than 1-2mm from the input distance, check all you parameters again. Is the wavelength really correct, as well as the distance? If you are sure about them, try indexing with only a few images  | |||
 SPOT_RANGE = 1 20  | |||