Crystal Structures Involving P, T, and O Layers

Abstract

We began with simple close-packed structures (ccp and hcp) encountered for metals and simple molecular elements and compounds. Because many metals have the body-centered cubic (bcc) structure under suitable conditions, we had to include this structure with the 3-2PTOT notation. Next we considered about 60 structures involving P and O layers. There were about 40 structures involving P and T layers, some of which are more complex because there are two T layers for each P layer. Now we consider structures involving P, T, and O layers. As earlier, we begin with simple cases. Some molecular species give structures based on a bcc pattern involving all layers occupied by the individual molecules. Then we consider compounds with structures similar to that of CsCl. If atoms of a CsCl-type structure were the same it would be bcc. These are 3-2PTOT structures with cations and anions occupying different layers. Next, we consider the more complex structures involving combinations of P, T, and O layers, some of which are partially filled. Finally, we consider structures involving P, O, and one T layer, including cases that have partially filled layers.