THE ELECTRON LOCALIZATION FUNCTION IN CLOSO BORON CLUSTERS

The structure and the electron density in the closo boron clusters B4X4 (X = H, Cl, Br, 1), B6X62-(X = H, Cl, Br, I) and B12H12- were determined by pseudopotential Hartree-Fock calculations. The Electron Localization Function (ELF) was used to interpret the bonding characteristics. The regions of high ELF values in all cases have the form of the dual polyhedron of the boron cage. They show perfectly the 3 center 2 electron bonds. The comparison between Hartree-Fock and Extended Huckel calculations point out that semiempirical calculations can also be a good basis for ELF interpretations.