团簇CoFe_2B_2稳定性的密度泛涵理论研究

The Density Functional Theory Study on Stability of Cluster CoFe_2B_2

运用密度泛函理论(density functional theory,DFT)方法,在Becke3LYP/Lanl2dz水平下,对团簇CoFe_2B_2各个可能的构型进行优化,最终得到9种优化构型。本文从动力学、热力学稳定性2个方面对这9种构型之间的异构化反应进行分析,发现异构化反应的限度受团簇热力学稳定性的影响,提出一种线性方程lnK=0.391 9ΔE+0.435 7以预测团簇异构化反应的限度;多数构型通过一种或多种通道向构型2^((2))转化;构型1^((4))、2^((4))两者之间的反应为可逆反应,构型1(2)无异构化反应发生并且具有很好的稳定性,最终存在构型为1(2)、2^((2))、1^((4))、2^((4)),即戴"帽"三角锥和四角方锥两类构型。

Abstract： Nine stable configurations were gairted after a series of cluster CoFezBz models were opttmtzect and calculated under the Becke3LYP/Lanl2dz level by using density functional theory （DFT） method. Isomerization reactions of those stable configurations were studied from thermodynamics and dynamics. A. logarithmic equation is proposed to predict the limit of isomerization reaction, namely InK =0.391 9 ΔE＋0.435 7; most of stable configurations were converted to configuration 2（2） through one or more doors and the isomerization reaction of configurations 1（4）/2（4） is reversible; there is no isomerization of configuration 1（2） taking place, and the final existence of cluster CoFezBz are configurations 1（2） 2（2） 1（4） 2（4） , namely capped triangular and quadrangular pyramid structures.