Quality Control

This is an attempt of putting together a number of datasets with different characteristics (high and low resolution, good and bad crystals, untwinned and twinned), their evaluation with different versions of XDS, and the determination of the quality of the resulting data using experimental phasing and refinement.

The goal of this project is to find generally optimal parameters for XDS data reduction, to monitor the progress of the program, and to discover bugs or regressions.

The metrics I would like to look at is

• anomalous signal: SHELXC anomalous correlations if two or more wavelengths available; SHELXD (fixed version) success rates and CCall/CCweak maximum values
• refinement of a given (known) set of heavy atom positions in (e.g.) SHARP (fixed version): r.m.s. or absolute phase difference, or map correlation w.r.t. phases from good model
• refinement with (e.g.) refmac5 (fixed version) of a given model, finding LL and R/R_free

The raw data (images) for the different datasets are either available from this site by FTP, or from the (publicly accessible!) JCSG dataset archive.

There's currently data available for (our own) 1t92 project (PulG), and the data for PDB id 1ZTV (JCSG target name TB1631F). I'm working with Qingping Xu on identifying further suitable JCSG datasets. A number of datasets (lysozyme, elastase, ...) will also be made available by Manfred S. Weiss and coworkers.