Hi Andrej We have docked a small peptide on the active site of protease molecule, now want to perform structural refinement and energy minimization. Can OPTIMIZE command of modeller do that or implementation of any energy minimizer is needed. Kindly note, OPTIMIZE successfully eliminate all short non-bonded contacts and improved stereochemical parameters of the initial enz-inhibitor complex.. Secondly, is it obligatory to use minimizer during these type of work. Advise please. Regards Kamran Azim