I am looking into double perovskite materials. One of the possible materials is Cs4CuSb2Cl12. Now, although there are a few papers which have done ab intio calculations but none of the common open databases have cif file for this structure(COD and materials project). The paper which I am currently looking into has submitted there data to ICSD, but I do not have access.
Due to which I have decided to start working on my own cif file. An older answer gave a brief description on how to do this using VESTA(and I am also comfortable with the software) , but I still have some doubts. Mainly how does one calculate the spatial coordinates of each atoms and how do we add the term U(which I suppose is the energy of some sort).
If anyone has any idea how I can obtain the cif file or how to go about finding the coordinates and finally making a cif file(please also mention what other information do I need apart from the space group and lattice parameters)