Hi, Bryan, Do not going into details of TLS, the very first remark is that the center of reaction that characterizes the MOVEMENT of the group is NOT AT ALL the center of mass that characterizes the GROUP as it is independently of any its movement. They should not be confused. Sacha -----Message d'origine----- De : [email protected] [mailto:[email protected]] De la part de Bryan Lepore Envoyé : mercredi 20 octobre 2010 00:01 À : [email protected] Objet : [phenixbb] refine : peculiar TLS tensors [ phenix 1.6.4-486 ] [ ALSO : tlsanl, refmac, etc. from ccp4 6.1.3 ] [ molscript/povscript ] the one-liner : i have some TLS tensors that sometimes do not compare at all well with refmac/anisoanl tensors. sometimes, the principal axes of a TLS tensor refines *very* far away from the center of mass(=center of reaction), or the axes from tlsanl are exceptionally small as if not scaled properly. the eigenvalues are really small too. see [*] for troubleshooting and strategy used. i suspect i am missing something. i also understand this might not be a phenix question. -bryan [*] i compared another .def that gave sensible TLS results with a different dataset/model, and my {} are all good AFAIK. anisoanl/refmac/parvati results are reasonable. the phenix refinement appears well behaved. these are all using tlsextract to get the eigenvalues/origins, and molscript to check the axes/centers of mass. input B factors are Beq unless i made an error. the tls group selections can vary - however, simple groups also can give these results. in general, using strategy (excerpt) : refine { strategy = *individual_sites individual_sites_real_space rigid_body \ *individual_adp group_adp *tls *occupancies *group_anomalous sites { individual = None torsion_angles = None rigid_body = None } adp { individual { isotropic = None anisotropic = None } group_adp_refinement_mode = *one_adp_group_per_residue \ two_adp_groups_per_residue group_selection group = None tls = "chain A and (resid 1:41 or resid 42:159 or resid 195:237 or resid 263:420)" tls = "chain A and resid 160:194" tls = "chain A and resid 245:252" } [...cut off ... ] example output of an ill-behaved S tensor from tlsanl : SCREW ROTATION AXIS ABSOLUTE POSITION (A) PITCH (A) X Y Z 1 70.667 154.197 308.627 -144.435 2 977.334 819.588******** 6222.947 3 640.7191431.084 471.341 269.382 _______________________________________________ phenixbb mailing list [email protected] http://phenix-online.org/mailman/listinfo/phenixbb