采用分子动力学方法,对含有100000个Al原子的液态金属系统在凝固过程中团簇结构的形成特性进行了模拟研究,并采用原子团类型指数法(CTIM)来描述各种类型的团簇结构组态.研究结果显示:在液态金属Al的凝固过程中,只有与1551键型相关的二十面体原子团(120120)及其组合形成的各种团簇结构,对微结构的演变起着关键的、决定性的作用;由不同数目、不同类型基本原子团组成的各种层次的团簇结构,都在一定的原子数区段内呈现出峰值,即幻数点;系统的幻数序列为:13(13),19(21),25～28(27),31～33(29～30),37、39,…(括号内为液态时对应的幻数值),与Harris等人的实验结果甚为相符.本模拟研究所用的团簇结构按层次区段来研究幻数序列的方法,可为实验结果提供更为合理的模型解释. The molecular dynamics method was used to simulate the formation behavior of the cluster structure during the solidification of a liquid metal system containing 100000 Al atoms. The atomic cluster exponent method (CTIM) was used to describe the cluster structure of various types The results show that during the solidification process of liquid metal Al, only the icosahedral groups (120120) associated with the 1551 bond and the various cluster structures formed by them combine to form the microstructure evolution. The decisive role; clusters of different levels and types of basic atomic clusters at various levels of the cluster structure, in a certain number of atoms in the section showed a peak or magic point; the magic number of the system is: 13 (13 ), 19 (21), 25-28 (27), 31-33 (29-30), 37,39, ... (the corresponding magic numbers in brackets), in good agreement with the experimental results of Harris et al. The cluster structure used in this simulation studies the method of magic number sequence by layer segment, which can provide a more reasonable model explanation for experimental results.