DENSITY-FUNCTIONAL CALCULATIONS OF STRUCTURES AND IONIZATION ENERGIES FOR HEAVY GROUP-V CLUSTER ANIONS

The structure and electronic structure of heavy-group V cluster anions (Sb-n(-), Bi-n(-)) are calculated with density functional methods within the local spin density approximation (LSDA). The influence of gradient corrections of the exchange and correlation energy is investigated. The calculated vertical and adiabatic ionization energies are in very good agreement with data from photoelectron spectroscopy (PES) for Sb-n(-), whereas the relatively large deviations for Bi-n(-), can he reduced by the consideration of relativistic effects in a scalar-relativistic manner. Concerning the structures, a strong similarity to the corresponding P-n(-) clusters was found. In particular, the negatively charged pentamers are planar rings (with similarities to the aromatic [C5H5](-) anion) with especially high ionization energies. (C) 1995 John Wiley & Sons, Inc