Dear all, I have a query related to symmetry imposition and corresponding tweaking of model. If symmetry (say, C4) was imposed during the reconstruction of a 3D volume, does symmetry also need to be imposed when building the atomic model (say, in Phenix)? Or could this constrain be relaxed? Do we need to tweak the model in Coot for other chains or since it is build on symmetrical partners therefore should only be made in one chain and copied for all without any fitting? Pramod Jaykar, Ph.D.