钠、铝团簇的电子亲合能、结构与原子数的关系研究

The Relationship Between Electron Affinity/Structure and the Clusters Size of Na_n/Al_n Clusters

根据静电球形液滴模型理论,结合钠、铝团簇不含3d轨道的特性,推导适合非3d轨道的团簇的电子亲合能与原子数之间符合的普遍规律EA(R)≈W∞+ae2/R,从而更方便的预测大尺寸团簇的性质参数。同时,根据晶体最密堆积原理分析了大尺寸Nan的表面结构,小尺寸Aln最稳定结构及Nan(n=20,34,40,…)、Aln(n=13和37)的明显幻数模型结构。

The change between the electron affinities, the structure and the clusters size is studied for So- dium clusters and Aluminium clusters. According to the Spheroidal JeUium Model, the new formula EA （R） = W∞ - ae2/R - b/R2 （ R = rsn1/3 ）, which was put forward by considering the polarization, the d - s hybridization in the atoms （or molecules） and the screening effect on the surface, is modified to EA（R） = W∞ -ae2/R for Nan and AIn without 3d orbitals. Then the EA values at the infinite size are close to the metal＇ s work functions, and excellent fitness are obtained from EA（ R） = W∞-ae2/R than EA（ R） = W∞ -ae2/R -b/R2 for Sodium clusters and Aluminium clusters because of lack of 3d orbitals. Meanwhile, Nan and Aln behave magic clusters, and the surface structures of large Sodium clusters and the stable structure of small Aluminium clusters are ana- lyzed in detail.