Re: [ccp4bb] xds and cell refinement in cP

[Kay Diederichs]

Jan Abendroth schrieb:

Hi all,
I am running into a strange behaviour fo xds for a primitive cubic data set.

Any ideas?

Thanks a bunch
Jan

Neither in the INTEGRATE nor in the CORRECT step the cell parameters are refined and stay exactly at the value specified in XDS.INP. R-factors and I/sigmas of the XSCALE run look suspiciously high/low. When I reduce the symmetry to tetragonal and run an otherwise identical XDS.INP script, the cell parameters are refined again.

Jan,


If you have, in XDS.INP,
REFINE(INTEGRATE)=DISTANCE CELL ....




HTH,

Kay
--
Kay Diederichs                http://strucbio.biologie.uni-konstanz.de
email: kay.diederi...@uni-konstanz.de    Tel +49 7531 88 4049 Fax 3183
Fachbereich Biologie, Universität Konstanz, Box M647, D-78457 Konstanz

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I think that in the cubic system you cannot refine cell and distance at the same time. and similar for REFINE(CORRECT) then XDS will keep the cell at the input value, and refine the distance. So just remove DISTANCE from both lines in XDS.INP to have it refine the cell instead. The fact that the "R-factors and I/sigmas of the XSCALE run look suspiciously high/low" is unrelated, I'd say.

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