Hi, yes, this is correct: phenix.refine offers NCS restraints only. Here are two parameters you may want to play with: ncs { coordinate_sigma=None b_factor_weight=None } This will set up specified values for all NCS groups. Try an array of values to see which value works best (monitoring Rfree and overall stereochemistry). The defaults are 0.05 and 10, for coordinates and ADP correspondingly. Making coordinate_sigma smaller makes the NCS restraints tighter. Alternatively, you can set set different values for each NCS group like in example below: ncs { restraint_group { reference=XXX selection=YYY coordinate_sigma=0.05 b_factor_weight=10 } restraint_group { reference=AAA selection=BBB coordinate_sigma=0.03 b_factor_weight=5 } restraint_group { reference=ZZZ selection=QQQ coordinate_sigma=0.01 b_factor_weight=2 } } Be careful to not deviate too much from the default coordinate_sigma=0.05 since it may results in overall stereochemistry distortion. Anyway, like I said above, try an array of values and see which works best (judging by Rfree and overall geometry). Please let me know if you have more questions. Pavel. Daniele de Sanctis wrote:
Dear all,
i'm refining a low resolution structure (3.2A) with four molecules in the asymmetric unit. I saw that phenix.refine doesn't allow constraints, so i'd like to change the restraints weight but i can't find the right keyword...
thanks for your help
d