Theoretical study of siliconsodium binary clusters. Geometrical and electronic structures of Si_nNa (n = 1-7)

The geometries, ionization energies and adsorption energies of siliconsodium binary clusters (Si_nNa, n=1-7) were studied with ab initio MO calculations. All the calculations were carried out at the restricted Hartree-Fock level of approximation for both closed and open shell systems. The structure of the most stable isomer of the Si_nNa clusters keeps the frame of the corresponding Si cluster unchanged. The electronic structure of Si_nNa is similar to that of the corresponding negative ions Si^-_n. The ionization energies of Si_nNa were evaluated with the ΔSCF method, and they become smaller than that of the corresponding Si_n as was reported experimentally.