密度泛函理论交叉梁系统的塑性动力响应分析
Title the Theoretical Study of the Features of CsXn(X=F,Cl)
Abstract
With the computational method,DFT,we calculated and studied the VDE,AEA
and geometry of metal halogenide clusters CsXn(X=Cl,F) which consists of
alkali metal atom Cs,and halogen atoms Cl,F, in order to explore whether
they were superhalogens.We took several possible clusters for per size of
clusters,then optimized the length of bonding with Gaussian 03.The
calculational results showed even though F and Cl were at the same main
group,different lowest energies were displayed when n=3,which told us the
different ways of clusters.At the base of optimized geometry,AEA and VDE
of these clusters were calculated.Result indicated that all the AEA and
VDE were larger than Cl atom which has the biggest EA in the halogen atom
(EA=3.62eV) when n ≥ 2,so all these clusters were superhalogens.in
addition,CsFn clusters’ VDE and AEA were larger than CsCln clusters’ when
n≥2 and n≠6,which suggested doping mental play a marked part in improving
the EA of clusters.
Keywords superhalogens clusters DFT electron affinity
目 次
1 引言 . 1
2 超卤素简介 . 4
3 计算方法 6
3.1 密度泛函理论（Density functional theory,简称 DFT） . 6
3.2 Gaussian 03软件简介 . 6
4 结果与讨论 12
4.1 CsFn(n=1-7)的结果与讨论 12
4.2 CsCln(n=1-7)的结果与讨论 .. 16
结 论 . 22
致 谢 . 23
参 考 文 献 .. 24
1 引言
阴离子由于具有强氧化性在材料科学占据着重要地位，元素周期表中氧化性最强
的是卤族元素，它们获得电子的能力可以用电子亲和能[1][2]
（electron affinity, 简称 EA）
来描述。在元素周期表中，电子亲和能最大的元素是 Cl 原子，其电子亲和能为 3.62eV。
而 F原子由于半径太小，在氟原子所占据的不大的空间中挤满了电子，这些拥挤在一
起的电子对外来电子产生异常强烈的排斥作用，削弱了原子核对外来电子的吸引力，
使 F的电子亲和能比 Cl 略小，为3.40eV。
电子亲和能是指一个体系在中性时的能量与体系带一个负电荷时的能量之差，即
体系得到一个电子后前后能量的变化值。对于中性团簇，电子亲和能定义为体系增加
一个电子后所释放的能量，反应体系俘获电子的能力。弛豫时间是动力学系统的一种