[phenixbb] low resolution data/parameter ratio

Hi All, I am struggling with low resolution data (3.6 A) and I am concerned about overfitting. I have a ratio of about 3 reflections per atom. Possible refinement scenarios would be a) coordinates+tls, b) coordinates, group_adp, tls or c) coordinates, individual_adp, tls. The last scenario seems to be pushing the limits. I wonder if there are studies, thoughts or opinions out there on which refinement scenario to use. Thanks for any comment on this, Gerwald