Dear All,
I have a question regarding the correlation of thermal parameters
and occupancies. If anyone could give some tips on achieving a
satisfactory conclusion/minimum during a refinement, it would be
greatly appreciated.
At the moment I refine the atomic positions then the Us until a
minimum is reached. If a U is particularly high, for instance, then I
check the occupancy of this site; sometimes partially occupied
sites are expected in the phases we study.
However, as the U is fixed at the refined value then this willeffect
the occupancy. As I understand it the refined U is for the
occupancy fixed during the refinement. Sometimes a change in the
occupancy is observed on refining. I then will alternate between
refining the occupancy and U until a minimum is reached.
Is a better strategy to fix the U at a value for the same atom type in
the phase and look at the effect this has on the occupancy?
Explainations, suggestions, tips, further reading welcome!
Caroline
Caroline Kirk
Solid State Research Group
Department of Engineering Materials
University of Sheffield
Sir Robert Hadfield Building
Mappin Street
Sheffield
S1 3JD
Telephone: 0114 222 6013
E-mail: [EMAIL PROTECTED]
