[ccp4bb]: strange scaleit output

[sameeta bilgrami <sameeta_b@yahoo.co.in>]

***  For details on how to be removed from this list visit the  ***
***          CCP4 home page http://www.ccp4.ac.uk         ***

dear all,
      i am trying to solve a structure through mir. i
have a native and three derivetive datasets of hg th
and ur. the space group is I4122.
      The scaleit logfile is showing some results that
i am not able to comprehend:
 Firstly the "acceptable isomorphous diffrence" that
it is giving for the my three derivatives is in the
range of 16 -25 which is very low as compared to the
acceptable differences shown in the example
tutorial(here the acceptable diffrence is 90 -95).
Does this mean that there is less heavy atom
incorporation, or these values may vary that much.
 Secondly, the R-deriv  for each of the derivative and
the native is coming out to be lower than the R-sym of
the native, though actually it should be higher. 
On the other hand, the R-der is showing a dip at the
middle resolution range of 3-4 A, which is a good sign
for a derivative.
What is going on? please explain wether my derivatives
are usable or not. What else can i do to ascertain the
quality of my derivatives.
      my R-cullis(centric) is 0.8. The phasing power
of the hg derivative is 0.5 but that of the other
derivatives is 0.2-0.3...could this be due to wrong
sites or is the phasing power really so less. Is there
any other way of knowing the quality of my
derivatives.
              Thanking you all for your kind
attention,
                                      sameeta Bilgrami
                            

________________________________________________________________________
Looking for a job?  Visit Yahoo! India Careers
      Visit http://in.careers.yahoo.com