Hi,

According to the phenix documentation, phenix.refine generates free R that are evenly distributed over the resolution, making sure that relatively thin resolution bins receive enough of reflections. The default behavior is to flag 5% of reflections up to a maximum of 2000. However, in some high-resolution structure, the percent for R-free test set which was generated by phenix.refine might be smaller than 1%， and it was a small percentage.  Are there anticles related to the generation of R-free flag by phenix?

Sincerely yours,
Shiheng Liu