Engin The PDBe provide a service to plot many different statistical properties in the PDB against other properties. The link is below. You can see that there is an option of RDiff which is the difference between R and R-Free for all structures that contain both data. Take a look at this first. There is a second parameter which you can set to resolution and this will allow you to draw a plot that you want. This will draw a 3D isometric plot which you can scale, and pick data points to view particular entries. http://www.ebi.ac.uk/pdbe-as/pdbestatistics/PDBeStatistics.jsp Regards Tom Oldfield >> Does anyone already have the PDB-wide R/Rfree gap versus resolution data >> (it does not seem that the PDB maintains one)? >> >> Ed. >> > The friendly people in Uppsala has something here by the name Harry > Plotter: http://xray.bmc.uu.se/gerard/supmat/eds/plotter.html > This might be somewhat dated now. > > Engin >