On 12/11/09 12:55 PM, rui wrote:

SO in the output pdb file, there are another set of lines start with ANISOU, what are those, should I keep those?

These are ADPs - Atomic Displacement Parameters, or B-factors. They are as important as atomic coordinates (almost) stored in ATOM records -:)

I turned on the optimze_wxc and optimize_wxu flags in the GUI, it does give better R/Rfree. Do I need to turn on every time or just use the optimized weights, where I can find those optimized weight? In log file?

Optimization of weights is usually time consuming and the default weights are just good most of the time. So I usually recommend running weights optimization as the last step to tune up your model. Of course there might be exceptions. Since optimal weight may be different from run to run, they are not stored in .def file for the next runs. Pavel.