Ab initio study of cyclic hexahalotriphosphazenes

Using standard ab initio methods, the electronic structure and optimal geometries of cyclo-(NPX₂)₃ (X = F, Cl) are investigated at the DZ+P basis set level. Out-of-plane π overlap populations for P-N bonds (evaluated as the contribution of a“₂ and e” molecular orbitais) are roughly two times greater than the in-plane gp ones evaluated as half the difference between the gross and net d orbital Mulliken populations on phosphorus belonging to é molecular orbitais.