Probing the electronic structures and properties of neutral and charged (n =2–10) clusters using Gaussian-3 theory.

Abstract: The structures and energies of small CaSi _n (n =2–10) species and their anions have been systematically investigated by means of the Gaussian-3 (G3) theory. The electron affinities have been presented and compared with those of MgSi _n and BeSi _n . The ground state structures for all of these species are found to be “substitutional structure”, which are derived from Si _{n +1} by replacing a Si atom with a Ca atom. The reliable adiabatic electron affinities of CaSi _n have been predicted to be 1.56eV for CaSi₂, 1.77eV for CaSi₃, 2.01eV for CaSi₄, 2.06eV for CaSi₅, 1.97eV for CaSi₆, 1.98eV for CaSi₇, 1.86eV for CaSi₈, 2.49eV for CaSi₉, and 2.32eV for CaSi₁₀. The dissociation energies of Ca atom from the lowest energy structure of CaSi _n clusters have been calculated in order to examine relative stabilities. Compared with those of BeSi _n and MgSi _n , the dissociation energies of Mg from MgSi _n are the smallest. The charge transfer of CaSi _n and BeSi _n has also been computed to further understand the interaction between the metal atom and the silicon clusters. [ABSTRACT FROM AUTHOR]