I'm a novice of coot and ccp4. Now I'm doing refinement using both refmac5 and coot.Here are some problems I'm facing. Really hope you can give me some suggestions.

1¡¢THE RESOLUTION OF THE DATA IS 2.5 angstrom. After first refinement of refmac5 I got R factor which is 0.26 and R FREE which is 0.31. My question is what the final R factor and R FREE should be after several rounds of refinement by refmac5 and coot.

2¡¢At which map level£¨e/A3 or rmsd£©should I refine the data by coot?

3¡¢Can you give me some tips and strategies about how to use coot to decrease R free? now I just use some basic tricks such as fit density and Ramachandran plot to refine the data.

Best regards,

Peter Chen