中文摘要：

基于密度泛函理论（DFT）Becke3LYP/Lanl2dz赝势基组水平下的团簇Sc3B2优化构型,对各构型的稳定性进行了探讨。从电子自旋密度分布、动力学和热力学三方面研究了优化构型之间的异构化反应。结果表明,构型外围和内部原子间的α和β电子的自旋密度分布均对团簇Sc3B2各构型的稳定性有一定影响,其中,最终稳定存在构型为1^（2）、2^（2）。异构化反应限度受反应物和产物热力学稳定性影响,可采用lnK=0.403 48ΔE-0.001 95预测未发现的团簇间异构化的反应限度。

英文摘要：

Understuding on the stable structures of transition metal boride can provide valuable information on its properties and the preparation of new materials. The stability of each optimized structure of Sc3 B2 cluster was investigated by density functional theory （DFT）Becke3LYP/ Lanl2dz pseudo potential basis set. Additionally, the electron spin density distribution was analyzed by both kinetics and thermodynamics of the isomerization reaction between these structures. The following results were obtained. The peripheral and internal a and 13 electron spin density distribution had a certain effect on the stability of the optimized structures of Sc3 B2 cluster, and the most stable structure of Sc3B2 cluster was determined to be 1（2~ , 2（2~. The limit of isomerization was affected by the thermodynamic stability of reactants and the products. To predict the extent of cluster isomerization reactions, a linear equation of lnK= 0. 403 48AE-- 0. 001 95 was established.