中文摘要：

利用基于密度泛函理论的第一性原理赝势方法,计算含有硫空位和铅空位的方铅矿的电子结构,并讨论空位缺陷对方铅矿可浮性的影响。计算结果表明,铅空位缺陷使方铅矿费米能级降低,带隙变窄;而硫空位缺陷则使方铅矿费米能级升高,带隙变宽,同时,方铅矿的半导体类型由p型变为n型。空位缺陷引起的电荷布居数变化改变晶体中电子运动的状态,从而影响方铅矿的浮选行为。

英文摘要：

Based on the first-principle method of density functional theory（DFT） and pseudopotentials,the electronic structures of PbS with vacancy defects were calculated,and the effects of vacancy defects on the flotation of PbS were discussed as well.The results show that Pb vacancy causes Fermi level to a lower energy,narrowing the band gap,while S vacancy causes Fermi level to a higher energy,increasing the band gap and changing the semiconductor type of PbS from p-type to n-type.Vacancy defects change the electric populations and the movement states of electrons,which results in the change of flotation behaviors of PbS.