Re: [ccp4bb] HKL2000 indexing problem

[Nic Steussy]

Our most common problem is an incorrect beam center.  The crystal we collect most frequently has large cell dimensions, so if the beam center is off even a bit it will bollix up the indexing.  What we usually do at the synchrotron is look for a refined beam center from the group there before us.  That has been our secret to success on a number of occasions. Nic out On 02/20/2012 07:28 PM, Peter Hsu wrote: Hi all, I recently collected a data set off a single crystal and have had problems with indexing it. Every time I go pick peaks for indexing it constantly picks peaks that are just slightly off the actual peak. After indexing, it would always be that 2 of the 3 cell dimensions would be fairly normal, while the 3rd would have some impossible value such as 1. On some other occasions if it manages to pick peaks properly, and every time I go to index it, it gives back an error that I don't have enough peaks picked to index (picked nearly 500). I've tried using a number of different images to index from and have run into the same problem. Has anyone else run into these problems? Does anyone have any idea what might be wrong w/my dataset and/or crystal? Thanks in advance for any insight, Peter -- ================================ C. Nicklaus Steussy, M.D., Ph.D. Purdue University csteu...@purdue.edu ================================