Abstract: |
Ab initio spin-density-functional calculations have been performed to study the equilibrium structural, electronic, and magnetic properties of Tcn and Tcn@C70 endohedral metalofullerenes. Our results indicate that C70 can encapsulate Tcn clusters with up to n=9 atoms. Except n=2, the formation of Tcn@C70 endohedral metalofullerenes is predicted to be exothermic when n≤5, while the encapsulation process becomes increasingly endothermic beyond n=5. When encapsulating into the C70 cage, the geometries as well as electronic structures of the Tc cluster undergo comparative changes. Especially, compared to the isolated Tcn clusters, the total magnetic moments of Tcn@C70 reduce significantly. The analyses of the orbital population, Hirshfeld population and density of states show that electrons transfer from the Tc cluster to the carbon cage through the Tc-C efficient hybridization, which is responsible for such reduction of the whole magnetism. |
Key words: Density functional theory, Endohedral metalofullerenes, Tcn@C70, Vienna ab initio simulation package |
FundProject: |
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内嵌金属富勒烯Tcn和Tcn@C70的理论研究 |
曾丽金, 邓珂*
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中国科学院国家纳米科学中心纳米标准与检测重点实验室,北京100190
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摘要: |
系统地研究了内嵌金属富勒烯Tcn和Tcn@C70的平衡态结构、电子和磁性性质.研究表明C70能够内嵌Tcn团簇(n≤9).除了Tc2团簇,当n≤5时,形成内嵌金属富勒烯Tcn@C70是放热的过程,而当n>5时,这种过程是吸热的.在内嵌过程中,Tcn团簇的构型和电子结构都发生了相当大的变化.与单独的Tcn团簇相比,Tcn@C70的总磁矩明显地降低.对体系的轨道分布,Hirshfeld分布和态密度进行了分析发现,在内嵌金属富勒烯体系里,电子可以通过Tc-C的有效杂化从Tcn团簇向碳笼转移,从而使得体系的整体磁性降低. |
关键词: 密度泛函理论,内嵌金属富勒烯,Tcn@C70 |
DOI:10.1063/1674-0068/28/cjcp1507140 |
分类号: |