KappaCCD: Denzo, SADABS and XPREP

This tutorial describes an alternative, and preferable, method of processing data from the kappaCCD when one or more fast scan(s) have been collected in addition to the main (slower) scans. It uses Zbyszek Otwinowski's Denzo and George Sheldrick's SADABS and XPREP as well as a bit of hand editing. The latter is needed because SADABS does not always treat overloads properly, at least with data converted by x2sad. We'll treat the 'fast' and 'slow' scans separately, eliminate overloads in the 'slow' scans, and then combine the 'fast' and (edited) 'slow' data with XPREP. The extra work is well worth it for improved data quality. You should seek help if you do not fully understand the process. In spite of its age, the KappaCCD still produces superb data from crystals that would have been rejected in most laboratories just a few years ago.

The tutorial is divided into six parts. The first covers integration with Denzo, so it is similar to the first part of the old tutorial. The second part runs through Scalepack in the usual way, but only because this is required for 'nreport' to work properly (not sure why that is!). The new stuff begins with part 3.

1) Extract the intensity data from the diffraction frames.
2) Run a first pass through with Scalepack.
3) Create '.sad' input files for SADABS.
4) Run SADABS separately for fast and slow scans.
5) Identify overload intensities and edit slow .hkl file.
6) Merge fast and slow scans in XPREP.