Hi Phenix folks, Have any crystallographers seen the phenomenon I've captured in these screenshots (linked below to save space), of concentric, semi-spherical, alternating layers of difference density? It seems to be localized at a valine side chain at the edge of the model and reflected across some two-fold symmetry. There's no heavy metal in the crystallization. Overall, the quality of the map and the model refinements are very good; everything has behaved as expected. We're just trying to diagnose this phenomenon and our searches for related descriptions have not yielded anything. https://livejohnshopkins-my.sharepoint.com/:f:/g/personal/drichma6_jh_edu/IgBkH0K7T1_0SL32jIPvr41DAYbp0ZSjTv_VH3TMb8bwd3s?e=CQgBnl Thanks! -- Dan Richman, PhD (he/him/his) Research Associate, James Berger Lab Dept of Biophysics and Biophysical Chemistry Johns Hopkins University School of Medicine mobile: 201-669-0967