Dear Kyriacos,

Just one thing to add to this suggestion from Herman:

I personally view and study the plots generated by the SCALA/TRUNCATE or AIMLESS/TRUNCATE route after XDS processing (in particular the plot of Rmerge values as a function of Batch number) to eliminate deviating batches from processing. Once I have done this, XDS/XSCALE/XDSCONV gives me very adequate results (you will notice that I am not particularly faithful to a single suite of crystallographic software but that I pick what I want from each program suite... :-) )

HTH,

Fred.

On 21/03/13 08:41, herman.schreu...@sanofi.com wrote:
Dear Kyriacos,

What kind of high-resolution data do you have?
In my experience, while Scala usually produces excellent results, it often 
fails miserably or even crashes due to too negative intensities in case of low 
redundancy data. E.g. if one does a second high-resolution scan with a high 
swing-out angle with little low-resolution data and friedel mates. I have not 
looked whether Scala could be stabilized by somehow restraining the scale 
factors or switching off some refinement parameters. Since we process with XDS, 
in these cases I use XSCALE for scaling, which does produce very good results.

My recommendation would be to process with XDS. By using the autoProc procedure 
from Global Phasing this is very easy, even for people who are normally not 
able to run a program without a GUI. You will then have to run XSCALE manually, 
which is again trivial once XDS had run correctly.

Good luck!
Herman

-----Original Message-----
From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Kyriacos 
Petratos
Sent: Wednesday, March 20, 2013 6:25 PM
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] Scaling with SCALA high and low resolution data sets

Dear All,

we have two data sets at about 0.9 and 1.9 Ang. resolution collected from a 
single crystal.
Integration with iMosflm seems to be fine like the scaling within each of the 
data sets.
When we try to merge and scale both of them with 'Scala' we get extremely high 
scale factors for the lower resolution images varying between approximately 30 
and 200!
Do we need to pay attention to some particular options for running the 
program(s)?
Thank you,

Kyriacos
e-mail: petra...@imbb.forth.gr




--
Fred. Vellieux (B.Sc., Ph.D., hdr)
ouvrier de la recherche
IBS / ELMA
41 rue Jules Horowitz
F-38027 Grenoble Cedex 01
Tel: +33 438789605
Fax: +33 438785494

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