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基于从体心立方碱金属晶体优化确立的多体展开势能函数，本文通过坐标优化研究了碱金属原子簇Ｘｎ（Ｘ＝Ｌｉ，Ｎａ，Ｋ，Ｒｂ，Ｃｓ）的结构和稳定性．发现：（１）Ｘｎ原子簇（ｎ＝４－２１）倾向于形成畸变四面体结构单元（Ｔｄ）的密堆积，分子表面被三元环（Ｄ３ｈ）所覆盖．其中Ｘ７－Ｘ１５最优结构中包含五角双锥Ｘ７（Ｄ５ｈ）结构单元，具有区域五重对称轴；（２）“微观晶体碎片”的分层优化结果表明，体心立方、面心立方及六方密堆积类展状原子簇具有相近的结合能．且均远比相应原子数的简单立方及金刚石类层状原子簇更为稳定；（３）原子簇的单原子平均结合能呈增大趋势，向体心立方碱金属晶体的结合能缓慢趋近．
Based on the multi-body developed potential function established from the body-centered cubic alkali metal crystals, the structure and the stability of Xn (X = Li, Na, K, Rb, Cs) clusters have been studied by coordinate optimization. It is found that: (1) Xn clusters (n = 4-21) tend to form a close packing of distorted tetrahedron structural units (Td), which are covered by a three-membered ring (D3h). Among them, the optimal structure of X7-X15 contains the pentagonal bipyramid X7 (D5h) structural unit with the region quintic axis of symmetry; (2) The hierarchical optimization results of “microcrystal fragments” Close-packed class of clusters like clusters have similar binding energy. And are far more stable than the simple cubic and diamond-like layered clusters with the corresponding number of atoms. (3) The average binding energies of the single clusters of the clusters show an increasing tendency, and the binding energy to the body-centered cubic alkali metal crystals slowly approaches .