Hi all
I am trying to run a refinement of a neutron and x-ray PDF in Topas 7. But I have run into this error message
My error messages looks like this, see the inp file at the end:
Space group F-43m is not centrosymmetric
Number of equivalent positions 96
G(r), approximate number of interactions: 18816
Unhandled exception in non_fit_10::calc_xdd_ycalcs_and_rwp
I can refine the x-ray PDF by itself and the neutron PDF by itself. I can also co-refine diffraction data along one of the PDF datasets, but when I combine them I get the error message above.
The error goes away if I give the structure a different space group for each dataset, but I do not understand why.
Both space groups can be non-centrosymmetric or centrosymmetric or one of each.
The structure is obtained from topas after a combined refinement of the Bragg data.
I can't find anything in the technical references or on the WIKI
Anybody knows what is going on?
My input file looks like this
xdd pristine_neutron_norm.xy
pdf_data
neutron_data
start_X 1
finish_X 16.5
dQ_damping(dQ, 0.02)
str
...
xdd pristine_xray_norm.xy
pdf_data
start_X 1
finish_X 16.5
dQ_damping(dQ, 0.01)
str
...
for xdds {
for strs 1 to 1 {
...
}}