Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 8 of 8
Full-Text Articles in Entire DC Network
Half-Metallicity In Hybrid Bcn Nanoribbons, Er-Jun Kan, Xiaojun Wu, Zenyu Li, Xiao Cheng Zeng, Jinlong Yang, J. G. Hou
Half-Metallicity In Hybrid Bcn Nanoribbons, Er-Jun Kan, Xiaojun Wu, Zenyu Li, Xiao Cheng Zeng, Jinlong Yang, J. G. Hou
Xiao Cheng Zeng Publications
The established chemical synthetic strategy toward graphene nanoribbons has greatly prompted and justified the research of theoretical designs of novel materials based on graphene. In this paper, we report the novel half-metallicity in C and BN hybrid zigzag nanoribbons even though stand-alone C or BN nanoribbon possesses a finite band gap. By performing first-principles electronic-structure calculations, we find this unexpected half-metallicity in the hybrid nanostructures stems from a competition between the charge and spin polarizations, as well as from the π orbital hybridization between C and BN. Molecular dynamics simulations indicate that the hybrid nanoribbons are stable. Our results point …
Anisotropy Of Crystal-Melt Interfacial Free Energy Of Silicon By Simulation, Pankaj A. Apte, Xiao Cheng Zeng
Anisotropy Of Crystal-Melt Interfacial Free Energy Of Silicon By Simulation, Pankaj A. Apte, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
We extend the cleaving wall method to a nonpairwise additive potential. Using this method, we compute the anisotropy of crystal-melt interfacial free energy γ for Stillinger–Weber potential of silicon [F. H. Stillinger and T. A. Weber, Phys. Rev. B 31, 5262 (1985)]. The calculated γ for (100), (111), and (110) orientations are 0.42±0.02, 0.34±0.02, and 0.35±0.03 J &#;m2, respectively. The anisotropy in γ we found is consistent with the experimental observation that Si(100)-melt interface develops (111) facets and also helps in explaining a higher undercooling observed for Si(111)-melt interface in Czochralski method.
Medium-Sized Double Magic Metal Clusters: Al@Cu54- And Al@Ag54-, Yi Gao, Nan Shao, Xiao Cheng Zeng
Medium-Sized Double Magic Metal Clusters: Al@Cu54- And Al@Ag54-, Yi Gao, Nan Shao, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
Medium-sized double magic metal clusters, Al@Ag54- and Al@54-, are predicted based on unbiased global search and density functional calculation. Both bimetallic core-shell clusters have icosahedral symmetry, and they are much lower in energies than all other low-lying isomers. In contrast, the icosahedral cluster Al@54- is a high-energy isomer. Both Al@54- and Al@Cu54- exhibit appreciable gaps between the highest occupied molecular orbital and the lowest unoccupied molecular orbital, and strong spherical aromaticity, which provide two additional evidences for the likelihood of their high stability. The simulated anion photoelectron spectra and …
Search For Lowest-Energy Structure Of Zintl Dianion Si122-, Ge122-, And Sn122-, Nan Shao, Satya S. Bulusu, Xiao Cheng Zeng
Search For Lowest-Energy Structure Of Zintl Dianion Si122-, Ge122-, And Sn122-, Nan Shao, Satya S. Bulusu, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
We perform an unbiased search for the lowest-energy structures of Zintl dianions (Si122-, 122-, and 122-), by using the basin-hopping (BH) global optimization method combined with density functional theory geometric optimization. High-level ab initio calculation at the coupled-cluster level is used to determine relative stabilities and energy ranking among competitive low-lying isomers of the dianions obtained from the BH search. For 122-, all BH searches (based on independent initial structures) lead to the same lowest-energy structure 12a2-, a tricapped trigonal prism (TTP) with Cs group symmetry. Coupled-cluster calculation, …
Structures And Relative Stability Of Medium- And Large-Sized Silicon Clusters. Vi. Fullerene Cage Motifs For Low-Lying Clusters Si39, Si40, Si50, Si60, Si70, And Si80, Soohaeng Yoo, N. Shao, Xiao Cheng Zeng
Structures And Relative Stability Of Medium- And Large-Sized Silicon Clusters. Vi. Fullerene Cage Motifs For Low-Lying Clusters Si39, Si40, Si50, Si60, Si70, And Si80, Soohaeng Yoo, N. Shao, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
We performed a constrained search, combined with density-functional theory optimization, of low-energy geometric structures of silicon clusters Si39, Si40, Si50, Si60, Si70, and Si80. We used fullerene cages as structural motifs to construct initial configurations of endohedral fullerene structures. For Si39, we examined six endohedral fullerene structures using all six homolog C34 fullerene isomers as cage motifs. We found that the Si39 constructed based on the C34(Cs:2) cage motif results in a new leading candidate for the lowest-energy structure …
Ab Initio Calculation Of Carbon Clusters. Ii. Relative Stabilities Of Fullerene And Nonfullerene C24, Wei An, Nan Shao, Satya S. Bulusu, Xiao Cheng Zeng
Ab Initio Calculation Of Carbon Clusters. Ii. Relative Stabilities Of Fullerene And Nonfullerene C24, Wei An, Nan Shao, Satya S. Bulusu, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
Chemical stabilities of six low-energy isomers of C24 derived from global-minimum search are investigated. The six isomers include one classical fullerene (isomer 1) whose cage is composed of only five- and six-membered rings (5/6-MRs), three nonclassical fullerene structures whose cages contain at least one four-membered ring (4-MR), one plate, and one monocyclic ring. Chemical and electronic properties of the six C24 isomers are calculated based on a density-functional theory method (hybrid PBE|PBE functional and cc-pVTZ basis set). The properties include the nucleus-independent chemical shifts (NICS), singlet-triplet splitting, electron affinity, ionization potential, and gap between the highest occupied molecular …
Electronic And Magnetic Properties Of Endohedrally Doped Fullerene Mn@C60: A Total Energy Study, Guangping Li, Renat F. Sabirianov, Jing Lu, Xiao Cheng Zeng, Wai-Ning Mei
Electronic And Magnetic Properties Of Endohedrally Doped Fullerene Mn@C60: A Total Energy Study, Guangping Li, Renat F. Sabirianov, Jing Lu, Xiao Cheng Zeng, Wai-Ning Mei
Xiao Cheng Zeng Publications
We perform total energy calculations on a manganese atom encapsulated inside a C60 cage using density functional theory with the generalized gradient approximation through three optimization schemes and along four paths inside the cage. We find that when Mn is located in the central region, its electronic and magnetic properties are not exactly the same as those of a free Mn atom due to weak coupling between Mn and the cage. As Mn is shifted toward to the edge, the total energy and spin start to change significantly when Mn is situated about one-third of the way between the …
Probing The Electronic And Structural Properties Of Doped Aluminum Clusters: Mal12- (M=Li, Cu, And Au), R. Pal, Li-Feng Cui, Satya S. Bulusu, Hua-Jin Zhai, Lai-Sheng Wang, Xiao Cheng Zeng
Probing The Electronic And Structural Properties Of Doped Aluminum Clusters: Mal12- (M=Li, Cu, And Au), R. Pal, Li-Feng Cui, Satya S. Bulusu, Hua-Jin Zhai, Lai-Sheng Wang, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
Photoelectron spectroscopy (PES) is combined with theoretical calculations to investigate the electronic and atomic structures of three doped aluminum clusters, MAl12- (M=Li, Cu, and Au). Well-resolved PES spectra have been obtained at two detachment photon energies, 266 nm (4.661 eV) and 193 nm (6.424 eV). Basin-hopping global optimization method in combination with density-functional theory calculations has been used for the structural searches. Good agreement between the measured PES spectra and theoretical simulations helps to identify the global minimum structures. It is found that LiAl12- (C5v) can be viewed as replacing a surface Al …