DENZO misindexing??

diane h peapus diane at kuchem.kyoto-u.ac.jp
Tue Oct 29 04:20:59 EST 1996


Greetings All:

   I've been struggling to process some data since May and thought I'd
ask now for any thoughts.

Data:
   Native data at 3.2A taken on lab device (DIP100)
   Non-isomorphous Hg cocrystal at 3.2A on DIP100

   Native high resolution taken at the Photon Factory
   5 MAD data sets on cocrystal high res at PF

Situation:
   DENZO process native data with no problem in about as long as it
takes me to set up the input files.  DENZObig process the native PF
data with comparable ease.
   DENZO process cocrystal home data after about a month of struggle.
DENZObig has so far failed to process cocrystal PF MAD data sets.

  The "difference" between successful and unsuccessful DENZO processing 
on the cocrystal data taken at home was that cryst rotx, roty and
rotz wildly flip-flopped between angles that were integral values
of 1/pi different... ie: 30 and/or 60 degrees difference between
unsuccessful and successful trial.  I'm in P6122.

Previous diagnosis:
   I was previously told that DENZO will often misindex if the beam
is not aligned and that I should re-align my beam and take more data.
I dont' think this is a feasible diagnosis because, 
   1) native data taken on the same machines within reasonable time 
      frames process just fine, 
   2) other lab members' data taken at the PF and on our home machine 
      during that time period process just fine, 
   3) low res cocrystal data taken at home _did_ process after about 
      a month of struggle, and 
   4) all misindexings of the cocrystal data taken at home were 
      integral values of 1/pi off.

   I think that DENZO is frantically flip-flopping between diagonal
and principle axes and doesn't know which to call what.

   Can anyone offer any suggestions?

   Any thoughts on the subject are greatly appreciated.

            diane h peapus




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