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[sdpd] overlapping reflections / preferred orientation



Hello All,

I am currently trying to solve the structure of an unknown 
Cu compound using FOX. The problem I am having is that 
although I am conviced that I should have layers or stacks 
of Cu (due to the magnetic measurements I have made) all 
the possible solutions that are proposed show an 
unchemical copper distribution (with regard to the Cu 
network and the O coordnation). This could be normal if I 
wasn't having a fit with quite good figures of merit (so I 
say...). I believe the problem arises because the two 
highest intensity  peaks at 13 and 29 degrees (CuKalfa12) 
are due to (2) overlapping reflections (this is a 
triclinic cell with two close lattice parameters) and 
therefore FOX tries to add electron density to the other 
HKL plane... The question I have is: can I be right? and 
is there any way around it? and (this is a FOX question) 
can I edit the HKL file so I force one reflection at a 
time to be responsible for the intensity?

Of course any other suggestions would be welcome

On another note a "theoretical question": in the same way 
one can derive the zero shift on a diffraction pattern by 
harmonic analysis without an internal standard, is there a 
way to derive a possible preferred orientation vector 
without a structural model? and where can I learn more 
about that?

thanks for your attention, if you read this far..

Antonio


 
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