Dear All,
Thank you for your responses so far and I apologize for not being clearer.
Here is the problem at hand: I have a material that is best thought of as organic, graphene-like 2-D sheets connected by infinite chains of Fe-S. Based on PXRD and other techniques, we know the structure of the AB plane (the 2-D organic part), but we aren't able to make sense of what is going on with the Fe-S chain. We can simulate the PXRD based on proposed .cif files, but it's off most likely because of the c direction (Fe-S chain).
We collected Fe K edge XAS to tease out Fe-S bond angles and distances, hoping we could feed this into our simulation for the PXRD to improve the fit.
Modifying the ATOMS input by hand, by constructing different reasonable geometries, was improving the simulation, but using a error minimization fitting program would be best.
So, is it possible to vary specific angles and distances between atoms along the c-direction only in an error minimization program based on our experimental data?
I apologize if you have already responded to this reformulated question.
best,
Carl