If I understand, the Ti are in coordinence 6, and the oxygen 3?

I understand that Z=4 means four formulas : 4 Ti, and 8 O.

Now express the positions of the four titaniums, then take the barycenters of the 3 coordinating titans for each oxygen. It may be the solution, assuming the higher symmetries for the oxygens.

Why don't you use software available on CCP14, e.g. PowderCell? It enables the automated generation of a primitive unit cell and their atom positions. The parallel generation of the diffraction patterns give the proof that both the old as well as the new cell description are identical (only differently described) if the generated diffractogram is identical.

https://www.researchgate.net/project/PowderCell-a-useful-tool-for-crystallographers-mineralogists-and-materials-scientists

Dear Gert,

Thank you very much for your prompt response. I could finally learn how to use from the wyckoff positions table to extract the atomic positions based on the space group and wyckoff positions.

Actually, I was rather interested to understand the basic procedure instead to use available softwares. By the way, thank you very much for your offer.

Below you can find fractional positions of Ti and O ( 0

But what the value should be use during refinement of the data. Is it 4 Ti positions and 8 O position coordinate in the programming or only one Ti and one O.

x y z

Ti 0 0 0

O 0 0 0.306

or

x y z

Ti

Ti

Ti

Ti

O

O

O

O

O

O

O

O

will be used..

Please clear it any body?