Subject:

**Adding Restraints for PDF Fittings**
Hi everyone again,

I have another question that I'm unsure of and can't really find much information on currently so I'm hoping someone may know more about this. I am attempting to fit some PDF data of a zeolite to a CIF file (generated from a DFT lowest energy calculation), and I am trying to add restraints to this. I have been allowing the atomic positions to refine, which unsurprisingly, gives a good fit but an incredibly unlikely crystal structure.

I have looked at a few tutorials and forum posts that use the "Distance_Restrain" macro, and I have attempted to incorporate this into the calculation but the experimental fit appears to simply flat line. I am unsure to whether this is due to the way I have set up the restraint or whether that this particular restraint is only useful for structure solution. If the latter, is there any other way to apply this kind of restraint for PDF.

Sorry for the length of this post, but any help on the matter would be greatly appreciated!

Daniel

I have another question that I'm unsure of and can't really find much information on currently so I'm hoping someone may know more about this. I am attempting to fit some PDF data of a zeolite to a CIF file (generated from a DFT lowest energy calculation), and I am trying to add restraints to this. I have been allowing the atomic positions to refine, which unsurprisingly, gives a good fit but an incredibly unlikely crystal structure.

I have looked at a few tutorials and forum posts that use the "Distance_Restrain" macro, and I have attempted to incorporate this into the calculation but the experimental fit appears to simply flat line. I am unsure to whether this is due to the way I have set up the restraint or whether that this particular restraint is only useful for structure solution. If the latter, is there any other way to apply this kind of restraint for PDF.

Sorry for the length of this post, but any help on the matter would be greatly appreciated!

Daniel