Electronic structures of the negative ions Si−2 –Si−10: Electron affinities of small silicon clusters

Abstract

Accurate ab initio calculations have been performed to investigate the structures and energies of the negative ions of Si₂–Si₁₀. The effects of polarization functions, diffuse functions, and electron correlation have been included in these calculations. In most cases, there is a good correspondence between the ground state structures of the negative ions and those of the corresponding neutral species. Adiabatic electron affinities are computed and compared with recent experimental measurements. Si₃, Si₅, Si₈, and Si₉ are found to have electron affinities which are larger than their neighbors. This result is interpreted using our previous calculations on the low‐lying states of the corresponding neutral species.