The equilibrium geometries,relative stabilities,and electronic properties of Ca2Sin(n=1–11)clusters have been systematically investigated by using the density function theory at the 6-311G(d)level.The optimized geometries indicate that the most stable isomers have three-dimensional structures for n=3–11.The electronic properties of Ca2Sin(n=1–11)clusters are obtained through the analysis of the natural charge population,natural electron configuration,vertical ionization potential,and vertical electron afnity.The results show that the charges in corresponding Ca2Sin clusters transfer from the Ca atoms to the Sin host.Based on the obtained lowest-energy geometries,the size dependence of cluster properties,such as averaged binding energies,fragmentation energies,second-order energy diferences,HOMOLUMO gaps and chemical hardness,are deeply discussed. The equilibrium geometries, relative stabilities, and electronic properties of Ca2Sin (n = 1-11) clusters have been systematically investigated by using the density function theory at the 6-311G (d) level.The optimized geometries indicate that the most stable isomers have three-dimensional structures for n = 3-11. The electronic properties of Ca2Sin (n = 1-11) clusters are obtained through the analysis of the natural charge population, natural electron configuration, vertical ionization potential, and vertical electron properties. show that the charges in the Ca2Sin clusters transfer from the Ca atoms to the Sin host. Based on the lowest-energy geometries, the size dependence of cluster properties, such as averaged binding energies, fragmentation energies, second-order energy diferences, HOMOLUMO gaps and chemical hardness, are deeply discussed.