Dear Alistair,
Erratic behaviour is often caused by the antibumping restraints because
they get switched off and on, and riding hydrogens and changes in the
occupancies can affect their action. This probably applies to both programs.
Any suggestions for improving the bulk solvent model in shelxl would be
welcome, it is clearly inadequate. Since shelxl can now input partial
structure factors using a/.fab/ file, this might be a good way of
testing other solvent models.
Best wishes, George
On 10/02/2014 09:07 PM, Alastair Fyfe wrote:
I would be grateful for any advice on how to obtain refmac
information equivalent in detail to the shelxl "Disagreeable
restraints before cycle N" listing. In the later stages of refining
a set of related structures, I have been alternating between shelxl
and refmac. Typically this relies on shelxl for occupancy assignment
of alternate conformations and associated partially occupied solvent,
followed by refmac on the shelxl result to improve bulk solvent
modeling. Most of the time this two step approach works well and
yields an improvement in the final model. However occasionally the
refmac step heads in the opposite direction:
Initial Final
R factor 0.1156 0.1390
R free 0.1192 0.1477
Rms BondLength 0.0108 0.0110
Rms BondAngle 1.3876 1.8731
Rms ChirVolume 0.1147 0.0979
This seems to happen rather erratically relative to changes in the
model and I've been unable to determine which restraints/weights are
responsible.
Thanks for any pointers,
Alastair Fyfe
UCSC
--
Prof. George M. Sheldrick FRS
Dept. Structural Chemistry,
University of Goettingen,
Tammannstr. 4,
D37077 Goettingen, Germany
Tel. +49-551-39-33021 or -33068
Fax. +49-551-39-22582
