[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[ccp4bb]: indexing - summary of replies

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

I would like to thank the following colleagues who tried to help me: 

Andrew Leslie, Jim Pflugrath, Ed Snell, Fred Vellieux, Manfred Buehner,
Eleanor Dodson, Sjors Scheres, Harry Powell, Andy Arvai, Ashley Deacon.

The suggestions/conclusions are as follows:
1) Always make sure these parameters are correct (which I did): Direct beam
position, Wavelength, Crystal to detector distance.
2) Andrew and Jim had a look at the images. They concluded: "the images look
much more like a precession photograph than an oscillation photograph (ie,
there are no clear lunes), which indicates either an extremely high mosaic
spread (in excess of five degrees) or the presence of multiple crystals
whose orientations are related in such a way that you get an apparent single
lattice. Some of the spots are also clearly split." 
3) Processing as P1 has been suggested.
I still believe this is an interesting case. I have made a snap shot of one
of the images:

If you are interested in looking at these images, please send me an email
and I will setup an ftp facility.

Quan Hao

> We have collected some data on station F1 at CHESS. The crystals
appeared to
> be hexagonal thin plates and diffracted to about 2.2A. We collected 75
> degrees of data for each of the three crystals. The spot shapes looked
> but we could not index the spots using DPS, DENZO or MOSFILM. The
> seemed to align along straight lines on all images and one could see
> hexagonal features. Has anyone come across this before? Your help is