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摘要：
The energy barriers and diffusion pathways for an adatom over curved surfaces of carbon nanotubes were studied by performing molecular dynamics simulations. Diffusion of the adatom was influenced by the average curvature of the surface. Positive curvature of the surface increased diffusion barrier and negative curvature decreased the barrier. Diffusion of the adatoms in axial direction was observed more easily in armchair nanotubes than in zig-zag nanotubes.
作者：
Shu D. J.;Gong X. G.
刊名：
Journal of Chemical Physics
在线出版时间：
2001

摘要：
The structures of (BaO) n (n≤9) clusters within density functional theory with generalized gradient approximations were systematically studied. Three structural growth modes were found for these clusters: cubic-like growth, ring-like growth, and anti-tetragonal prism based growth modes.
作者：
Chen G.;Gong X. G.;Liu Z. F.
刊名：
Journal of Chemical Physics
在线出版时间：
2002

摘要：
The interaction of a singlet ¹ Δ g O 2 with carbon nanotubes was reexamined by first principles calculations. Results lead to the conclusion that when the electron spin is treated correctly, the chemisorption of singlet O 2 occurs readily on the walls of (8,0) and (6,6) tubes, and the final products are energetically more stable than the physisorbed triplet O 2 .
作者：
Chan Siu-Pang;Chen Gang;Gong X. G.;Liu Zhi-Feng
刊名：
Physical Review Letters
在线出版时间：
2003

摘要：
We have studied the atomic structures of small Ba n O m (m < n < 9) clusters, using the density functional theory with the generalized gradient approximation. A structural transition was found during the uptaking of oxygen atoms into Ba n clusters. Initially, the frame of a Ba n cluster is kept unchanged, while oxygen atoms occupy the tetrahedral positions. As the number of oxygen atoms exceeds a certain limit, a transition from the compact to cubiclike structure takes place, with an increasing highest occupied molecular orbital–lowest unoccupied molecular orbital gap. In contrast to other ionic clusters, segregation of Ba atoms was not observed in our calculations, in agreement with reported experiments. © 2003 The American Physical Society.
作者：
Chen G.;Liu Z. F.;Gong X. G.
刊名：
Physical Review B Condensed Matter and Materials Physics
在线出版时间：
2003

摘要：
The chemisorption of NO 2 on carbon nanotubes is studied by modeling the interaction between NO 2 and N 2 O 4 with an infinitely long (8,0) single-walled carbon nanotube, using planewave/pseudopotential-based density functional theory (DFT). In sharp contrast to the case of graphite, for which NO 2 adsorption is physical, a NO 2 radical could readily adsorb on the exterior of an (8,0) tube by addition, similar to the reaction between NO 2 and alkenes. The process is slightly endothermic and reversible with a low energy barrier, with the NO 2 group in either the nitro or nitrite configuration. Adsorption of a second NO 2 is considerably exothermic, and desorption of NO 2 from such a configuration is much more difficult. The chemisorption of NO 2 also increases the conductivity of the (8,0) tube. On the other hand, N 2 O 4 only plays a minor role in the equilibrium between desorption and adsorption processes. These results indicate that the (8,0) tube is more reactive toward NO 2 than graphite, due to the curvature on the rolled graphene sheet.
作者：
Yim Wai-Leung;Gong X. G.;Liu Zhi-Feng
刊名：
Journal of Physical Chemistry B
在线出版时间：
2003

摘要：
We report results of the atomic and electronic structures of Al 7C cluster using ab initio molecular dynamics with ultrasoft pseudopotentials and generalized gradient approximation. The lowest energy structure is found to be the one in which carbon atom occupies an interstitial position in Al7 cluster. The electronic structure shows that the recent observation [Chem. Phys. Lett. 316, 31 (2000)] of magic behavior of Al7C^- cluster is due to a large highest occupied and lowest unoccupied molecular orbital (HOMO-LUMO) gap which makes Al 7C^- chemically inert. These results have further led us to the finding of a new neutral magic cluster Al7N which has the same number of valence electrons as in Al7C^- and a large HOMO-LUMO gap of 1.99 eV. Further, calculations have been carried out on (Al7N)2 to study interaction between magic clusters. © EDP Sciences Società Italiana di Fisica Springer-Verlag 2002.
作者：
Sun Q.;Wang Q.;Kumar V.;Kawazoe Y.;Gong X. G.
刊名：
European Physical Journal D
在线出版时间：
2002

摘要：
The geometric structures and magnetic properties of small FenB clusters have been studied by using a linear combination of atomic orbitals approach with the density functional formalism, and the Kohn-Sham equation is solved self-consistently by the discrete variational method. It is found that it is favourable for the B atom to locate at the surface, not at the centre of the cluster, and that the tetrahedron for Fe4B and the triangular prism for Fe6B clusters are not the most stable structures. When one atom in an Fen+1 cluster is replaced by a B atom, forming an FenB cluster, the binding energy increases, while the moment of the Fe atom decreases. It is indicated that the environment and doping play important roles as regards the stability and magnetic properties of clusters.
作者：
Sun Q.;Gong X. G.;Zheng Q. Q.;Wang G. H.
刊名：
Journal of Physics Condensed Matter
在线出版时间：
1996

摘要：
We present studies on both the electronic and magnetic properties of LaCo13 and La(FexAl1-x)13 intermetallic compounds by cluster model calculations within the scheme of density-functional theory. The equilibrium structures of the isolated and embedded clusters, obtained by minimizing the total binding energy, are in good agreement with available experimental data and other theoretical results. The relative stability and formation of LaCo13 and La(Fe xAl1-x)13 phases have been successfully explained. Interesting changes of magnetic properties in an Al doped Fe 13 cluster have been obtained. The possible effect of Al on the magnetic phase diagram of La(FexAl1-x)13 is discussed.
作者：
Zhang G. W.;Gong X. G.;Zheng Q. Q.;Zhao J. G.
刊名：
Journal of Applied Physics
在线出版时间：
1994

摘要：
The structural and electronic properties of Ba n O m cluster were disucssed using density-functional calculation within local density approximation. The ground-state structures of Ba n O m clusters were classified into compact, dangling state, F-center and stoichiometric. It was found that the compact cluster was metallic and no energy gap existed between the highest occupied and the lowest unoccupied molecular orbital. Analysis shows that the energy gap for the dangling state cluster was larger than that for the F-center cluster.
作者：
Chen G.;Liu Z. F.;Gong X. G.
刊名：
Journal of Chemical Physics
在线出版时间：
2004