Hello all, I hope everybody is doing well. Happy New Year 2021!!! I am stuck with some unusual behavior of restrain files generated by Phenix.ReadySet. I crystallized the protein with ligands which have double bonds between the atoms. As I see clear electron density for the ligand, I drew a ligand molecule in Coot (Ligand builder) and fitted in electron density very nicely. Until here, I can see the double bonds in the modelled ligand. I generated the restrain files using Phenix.ReadySet to further proceed for refinement. Unfortunately, after refinement the double bonds were converted to single bonds. I tried to generate new restrain files and refined the model, resulting in similar output. But, fortunately in one case, the double bonds were retained after refinement also. I tried to repeat with other ligands, where I was unsuccessful to retain the double bonds. please help me. Thank you so much. Regards Sharan -- Sharan Karade Postdoc-fellow IBBR-UMD, 9600 Gudelsky Dr, Rockville Maryland 20850