Geometries, stabilities and electronic properties of beryllium-silicon BeSi clusters.

The equilibrium geometries, growth patterns, stabilities, and electronic properties of bimetallic BeSi ( n = 1-11) clusters are systematically investigated at the B3LYP/6-311G(d) level of theory. Harmonic vibrational analysis has been performed to assure that the optimized geometries are stable. The optimized results suggest that the three-dimensional structures are observed for the most stable isomers of BeSi clusters when n > 2. The calculated vertical ionization potential for the lowest-energy isomers are comparable to the experimental values of Si. According to the averaged binding energy, fragmentation energy, second-order energy difference and HOMO-LUMO gaps calculations, we identify that the BeSi and BeSi clusters are more stable, and Be atoms doping enhance the chemical reactivity of the Si host. The natural population and natural electron configuration analyses indicate that the Be atoms possess positive charge at n = 1-5 but negative charge at n = 6-11. The chemical hardness of BeSi clusters show three local maxima at n = 2, 5, and 9, whereas three local minima are found for the corresponding chemical potential, meaning these clusters are more stable than their neighboring cluster sizes. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]