Dear all,

I am writing to see if anyone has had any success in solving the structure of compounds for which the stoichiometry is known and the constituents of the crystal structure known, but the repeating unit is unknown?

In my case, I am working with borates, who can coordinate both trigonally (BO3) and tetrahedrally (BO4) to oxygen. The unknown crystalline structure I am looking to solve contains both these trigonal and tetrahedral borates, but I do not know in what proportions/how they are interlinked. I do not either know whether infinite chains/3D networks are formed, or if individual/separate structural units make up the crystalline structure (although it is probably the former). Simply running the structure solve module with individual Boron and Oxygen atoms as motion groups leads to impossible structures. I have also tried running the crystal solve using some BO3 and some BO4 groups, to no avail. Is there any way to facilitate the structure solving of such a compound? I guess the same question applies to silicates, who have likely been more investigated than borates, and for which some methods/guidelines exist?

Thank you in advance for your help.

Best,

David