Recently,Wangs group produced a set of M@Sn12-cages (M=Ti,V,Cr,Fe,Co,Ni,Cu,Y,Nb,Gd,Hf,Ta,Pt,Au) by laser vaporization and characterized them by photoelectron spectroscopy.Both experimental and our calculations shows that these clusters have perfect or pseudo-icosahedral symmetry,with the central atom inducing very little distortion in the Sn122-cage.Since the central atom in M@Sn12-maintains its quasi-atomic nature,as in the endohedral fullerenes,the clusters are a rich class of potential building blocks for new materials with tunable electronic,magnetic,or chemical properties.The current work is a continuation of our interest in endohedral stannaspherenes.Extensive DFT calculations are performed to optimize the geometric structures of both the anion and neutral clusters of ZnSn12,to simulate the PES spectra,and to analyze the chemical bonding.