Dear all, I have a dataset at 2.98 A resolution, images processed to CC_1/2 at circa 50% in the last resolution shell, tetramer in the asymmetric unit, local (rotational) symmetry 222. Xtriage indicates a peak in the Patterson function at 20% height of origin peak, at fractional coordinates of 0.0000 0.0000 0.3177. Space group is P21. I am aware that this brings problems to refinement , as even stated at xtriage output "Translational pseudo-symmetry is very likely present in these data. Be aware that this will change the intensity statistics and may impact subsequent analyses, and in practice may lead to higher R-factors in refinement.", and so I can't lower my R and R-free below ~31 and 36 % , respectively. At phenix.refine, setting "tncs_correction = True" brings little benefit (what does this actually do? points to references are welcome). I wonder nevertheless if some strategy might help in on lowering these R's and, of course, allow me to build a better model (in spite of the resolution). I tried some combinations of other types of ncs and tls groups, with little success. Particularly, it seems that the refinement of ADPs are a kind of unstable (what I would understand come from the - partial - modular nature of the intensities - due to tncs - and these - ADP - would be reflected by the intensity fall-off with resolution). What about refining ADPs only to a zone which is not affect by data modulation? How to do that? Any other ideas? Thanks, Jorge