Si_n/Si_n^-(n=7~10)的结构和电子亲合能的研究

Structure and Electron Affinity of Silicon Si_n/Si_n^-(n=7~10)

选用4种不同的密度泛函理论方法(B 3LYP,BLYP,BP 86,B 3P 86),在全电子的双ζ加极化加弥散函数基组(DZP++)下,对S in/S in-(n=7~10)体系进行研究,获得它们的基态结构和电子亲合能.预测S i7/S i7-,S i8/S i8-,S i9/S i9-和S i10/S i1-0的基态结构分别为D5h(1A1′)/D5h(2A2)″,C2h(1Ag)/C3υ(2A2),Cs(1A′)/Cs(2A′)和C3υ(1A1)/C3υ(2A1).理论预测S i7,S i8,S i9和S i10的电子亲合能分别为1.90,2.59,2.07和2.20 eV,BLYP方法预测的电子亲合能最为可靠的.

Four kinds of density functional theory （DFT） methods （B3LYP, BLYP, BP86, and B3P86） are employed to predict the molecular structures and adiabatic electron affinities of Sin/ Sin^-（n= 7-10） species. The basis set is double-ξ plus polarization quality with additional s-and ptype diffuse functions, labeled as DZP＋＋. The ground states of Si7/Si7^-, Si8/Si8^-, Si9/Si9^-, and Si10/Si10^- are D5h （ ^1A1′ ）/D5h （^2A2＂）, C2h （^1Ag ）/C3v （^2A2）, C8 （ ^1A′ ）/C5 （^2A′）, and C3v （ ^1A1 ）/C3v （^2A1） respectively. Compared with the experimental values, the BLYP method is the best for electron affinities. The electron affinities corrected by zero-point vibrational energies for Si7, Si8, Si9, and Si10 are 1.90, 2.59, 2.07, and 2.20 eV, respectively.