Hello, I am refining a 3.0 A data set. Initially, I calculated the map at 3.5 A. I have now extended the resolution to 3.0 A, and I imported the FreeR-flags into the 3.0 A .sca file from the 3.5 A file. When I use the 3.0 A .mtz file, phenix.refine gives me this error- --------------------------------------------- The MD5 checksum for the R-free flags array summarized above is: 2ee90dd0a36800bb94370f83daf01698 The corresponding MD5 checksum in the PDB file summarized above is: 2e1cdfda59def2c4fb80ea6f1e452566 These checksums should be identical but are in fact different. This is because the R-free flags used at previous stages of refinement are different from the R-free flags summarized above. As a consequence, the values for R-free could be biased and misleading. However, there is no problem if the R-free flags were just extended to a higher resolution, or if some reflections with no data or that are not part of the R-free set have been added or removed. In this case, simply remove the REMARK r_free_flags.md5.hexdigest 2e1cdfda59def2c4fb80ea6f1e452566 record from the input PDB file to proceed with the refinement. Otherwise it is best to recover the previously used R-free flags and use them consistently throughout the refinement of the model. Run this command again with the name of the file containing the original flags as an additional input. ---------------------------------------- Why does phenix.refine give me this message when I have imported the FreeR-flags from the low resolution file? And what should I do about fixing it? Thank you for all suggestions. Saif Purdue University