I'd also comment that the absolute values are quite large. Well, I have no
knowledge what groups you've chosen, but for domain-sized groups, typical
values are 1-10 deg**2. Values can be larger for smaller TLS groups. This is
just a rule-of-thumb, but would make me suspicious whether the TLS refinement
was really stable in this case.
Regards
Martyn
-----Original Message-----
From: CCP4 bulletin board on behalf of Richard Gillilan
Sent: Sun 2/25/2007 1:10 PM
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] TLSANL: negative mean-sq displacements?
After TLS refinement (which seemed to be stable and produced nice
R_free values), I have analyzed the rigid body results with TLSANL.
I get negative mean-square displacements along the axes of libration
WRT to orthogonal axes! Am I misunderstanding something here? The
units are (deg^2). I see this with two different structures. Here is
the output from TLSANL:
AXES OF LIBRATION WRT TO MEAN-SQUARE ANGLE LIBRATION AXES MAKE TO
ORTHOGONAL AXES (IN ROWS) DISPLACEMENT ORTHOGONAL AXES (DEG)
ABOUT AXES (DEG^2) X Y Z
0.842 0.197 0.502 -53.975 32.66 78.63 59.85
-0.494 0.657 0.570 193.421 119.60 48.97 55.24
-0.217 -0.728 0.650 -12.276 102.55 136.73 49.45
MEAN LIBRATION (TRACE/3) 42.390
Anyone seen this happen before?
Richard Gillilan
MacCHESS
