Inorganic nanotubes and fullerenes structure and properties of hypothetical phosphorus fullerenes

The possibility of stable non-carbon fullerenes is discussed for the case of phosphorus fullerene-like cage structures. On the basis of Density Functional Tight Binding calculations it is shown that many such cages correspond to metastable structures, but with increasing nuclearity become less stable with respect to separate molecular P₄ units. Stability rules, known for carbon fullerenes, such as the "isolated pentagon rule", do not reflect the different electronic and steric requirements of the phosphorus atom. The computational results tend to rule out phosphorus fullerenes.