| Abstract: Four different density functional theory (DFT) methods (B3LYP, B3P86, BLYP, and BP86) have been employed to predict the molecular structures and adiabatic electron affinities of the SinH/SinH- (n=3～8) species. The basis set used in this study is of double-ζ plus polarization quality with additional s- and p-type diffuse functions, labeled as DZP++. The ground states of Si3H/Si3H-，Si4H/Si4H-，Si5H/Si5H-，Si6H/Si6H-，Si7H/Si7H-, and Si8H/Si8H- are C2v(2B2)/C2v(1A1) H-bridged structures, Cs(2A′)/Cs(1A′)，C2v(2B2)/C2v(1A1)，C2v(2B2 or 2B1)/C4v(1B1)，C5v(2B1)/C5v(1B1) and Cs(2A″)/C3v(1A1), respectively. Compared with the experimental values, the B3LYP in all of these schemes is the best in respect of predicting electron affinities. The electron affinities corrected by zero-point vibrational energies for Si3H，Si4H，Si5H，Si6H，Si7H,and Si8H are 2.56, 2.59, 2.84, 2.86, 3.19, and 3.14 eV, respectively. |
