Hi everyone, I am currently working on an X-ray/neutron (XN) joint refinement using phenix.refine. As it should be, H/D coordinates and ADPs at exchangable sites are refined to equal values when using Phenix version 1.10.1-2155 and neutron data only. This is also stated in the paper describing the development of the method (Afonine et al. (2010) Joint X-ray and neutron refinement with phenix.refine. Acta Crystallogr D Biol Crystallogr 66, 1153-1163) as the default behavior: "Currently, phenix.refine maintains the H and D atoms at coinciding positions and constrains their ADPs to be equal to each other". However, when switching to XN-refinement using the same Phenix version, H and D atoms refine to different coordinates and ADPs, which should not be the case as it leads to unrealistic artifacts as can be seen from the deposited PDB 3X2P: ATOM 186 H AALA A 13 3.486 -18.200 -14.123 0.38 14.54 H ATOM 187 D BALA A 13 3.488 -18.195 -14.111 0.62 38.07 D In this example, the D-occupancy is likely overestimated, while the H-occupancy is underestimated because the ADPs refine to very different values, which is chemically not reasonable. Hence my question: How can I treat my data in a way that ADPs and coordinates refine to the same values at exchangeable H/D sites also for XN-refinement? Is there a specific keyword I am currently overlooking or do I have to use another Phenix version? I would be really glad to receive your feedback. Thanks in advance! Kind regards, Johannes