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不同构型Al13团簇的合成模拟研究

calculation study on the synthesis of Al13 cluster with various configuration

中文摘要英文摘要

基于CI-NEB理论发展的MEP方法,结合DMol3程序LST/QST方法,计算并分析了不同结构形态Al13团簇在Al6+Al7→Al13下的形成过程,结果表明:团簇合成存在两个阶段:初始变形阶段与随后的结构演变阶段。在初始变形阶段,反应物中的亚稳组态会先转变成稳定结构(如C5v-Al6→Oh-Al6)。在结构演变阶段,对于具有晶体结构单元特征的团簇合成,若具有非晶结构单元特性的团簇参与合成时,则反应存在结构演变能垒,而参与合成的团簇都是晶体型结构时,则反应是一自动放热过程;对于含有五次对称元素的非晶团簇合成,在反应物中若存在具有非晶结构单元特征的Al7团簇时,演变过程无能垒或能垒很小,其中能垒的产生是由于晶体型团簇向非晶型团簇演变过程中五次对称性的引入。

Using a molecular orbital DMol3 program and the transition state search method of LST/QST based on the minimum energy path (MEP) in the climbing image nudged elastic band (CI-NEB) theory, the synthesis of non-crystal Ih-Al13 and crystal Oh-Al13-Al13 clusters are investigated in a bi-cluster association mode, i.e.Al6+Al7→Al13. The results show two stages exist in the synthesis reaction. That is the initial distortion stage and the subsequent configuration revolution stage. In the first stage, the metastable structures are forced to change into stable structures, e.g., C5v-Al6→Oh-Al6. In the configuration evolution stage, there are two different evaluation tendencies. For the synthesis of crystal clusters it is an automatic exothermic reaction if all reactants being of typical crystal symmetrical elements, e.g., Al6+Al7M→Oh-Al13. In the case of synthesis of non-crystal Ih-Al13 and Oh-Al13, an energy barrier must be overcome. However, the participation of D5h-Al7 with a fivefold symmetrical axis can make this association energy barrier decreased, e.g., Al6+Al7→Ih-Al13. Hence, the pre-existing and maintenance of the five-symmetry structures has a crucial role in the formation of metallic glass.

韩绍昌、李贵发、彭平

化学晶体学

ln团簇生长与合成密度泛函理论线性同步转变方法

ln clustergrowth and synthesisDFTLST/QST

韩绍昌,李贵发,彭平.不同构型Al13团簇的合成模拟研究[EB/OL].(2012-03-19)[2025-08-18].http://www.paper.edu.cn/releasepaper/content/201203-546.点此复制

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