[phenixbb] refinement with a covalent inhibitor.

Hi all, I am trying to refine a complex with a covalent inhibitor (E-64) that has a carboxylate group. My model has it planar, but after refinement the two oxygens of the carboxyl group get out of the plane. In the cif file generated by elbow this plane description is missing, I added it manually, but the result is the same. Maia