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Du J.,Sichuan University | Sun X.,Sichuan Agricultural University | Chen J.,State Key Laboratory of Surface Physics and Chemistry | Zhang L.,University of Sichuan | Jiang G.,University of Sichuan
Dalton Transactions | Year: 2014

A high-stability icosahedral cluster (Ta12 2+) with spherical aromaticity was found within a DFT framework. The spherical aromaticity of the icosahedral Ta12 2+ cluster was confirmed by a high symmetry, a short bond length, a high vibrational frequency, a large HOMO-LUMO gap and negative NICS(0) values. The icosahedral Ta 12 2+ cluster is the first example of a bare metal cluster with a total of 58 valence electrons. The electron density topological analyses (QTAIM and ELF) indicate that three-center shared interactions exist in the icosahedral structure. The IR and absorption spectra were theoretically simulated as a convenient way to confirm the existence of the icosahedral structure in further experiments. This journal is © the Partner Organisations 2014.

Sun X.,University of Sichuan | Du J.,University of Sichuan | Zhang P.,State Key Laboratory of Surface Physics and Chemistry | Jiang G.,University of Sichuan
Journal of Cluster Science | Year: 2010

Eleven kinds of density functionals in conjunction with three different basis sets are employed to investigate the homonuclear 5d-electron dimers: Hf2, Ta2, Re2, W2 and Hg2. The computed bond lengths, vibrational frequencies and dissociation energies of these molecules are used to compare with available experimental data to find the appropriate combination of functional and basis set. The different functionals and basis sets favor different ground electronic state for Hf2 and Re2 molecules, indicating that these two dimers are sensitive to the functionals used. The molecular properties of Hg2 dimer depend strongly on both functionals and basis sets used. It is found that the BP86 and PBEPBE functionals are generally successful in describing the 5d-electron dimers. For the ground states of these dimers, the bonding patterns are determined by natural bond orbital (NBO) analysis. Natural electron configurations show that the 6s and 5d orbitals in the bonding atoms hybrid with each other for the studied dimers except for Hg2. © 2010 Springer Science+Business Media, LLC.

Chen H.,State Key Laboratory of Surface Physics and Chemistry | Sang G.,State Key Laboratory of Surface Physics and Chemistry
Corrosion and Protection | Year: 2010

The tritium permeation is urgent problem to be solved in the test blanket module (TBM) tritium system The preparation methods of aluminide coatings and the mechanism of tritium permeation barrier (TPB) are presented. The microstructure formation mechanism and application in TPB of hot-dipped aluminum( HDA) are introduced. The HDA is a potential technology for preparing TPB on stainless steels due to its high permeation reduction factor (PRF) and being applicable for huge and complicated workpieces.

Du J.,Chengdu University of Technology | Sun X.,Chengdu University of Technology | Chen J.,State Key Laboratory of Surface Physics and Chemistry | Jiang G.,Chengdu University of Technology
Journal of Physical Chemistry A | Year: 2010

The structural, electronic, and magnetic properties of iridium clusters with sizes of n = 2-15 are investigated by employing the generalized gradient approximation of density functional theory. Simple cube evolution pattern is revealed for Ir2-15 clusters, as predicted by previous reports. It is remarkable that for Ir10, Ir11 clusters, new generated isomers with higher stabilities relative to those reported in previous studies are obtained. The even-sized clusters are more stable than the odd-sized species. The Ir-Ir bonds in the cubic Ir8 and Ir12 clusters, which are considered as the basic units in the structural evolution present covalent character. Starting from n = 8, the magnetic moments of Ir n clusters decrease sharply. The moments of magnetic clusters show 5d characters. The reactive site selectivity of studied clusters with n = 5-15 is analyzed with condensed Fukui function. The capped atoms in certain clusters (Ir9, Ir10, Ir11, and Ir13) generally show extraordinary activity for both nucleophilic and electrophilic attack. © 2010 American Chemical Society.

Du J.,University of Sichuan | Sun X.,University of Sichuan | Chen J.,State Key Laboratory of Surface Physics and Chemistry | Jiang G.,University of Sichuan
Journal of Physics B: Atomic, Molecular and Optical Physics | Year: 2010

The geometrical structures, electronic and magnetic properties of pure and B-substituted titanium clusters are determined by employing the density functional theory with gradient correlation functional and spin-unrestricted all-electron treatment. The isomers with a B atom located on the surface are energetically favoured for most of the studied clusters except Ti12B. The B atom enhances the stabilities of host clusters. The charge transfers from Ti to B atom together with s-p and s-d hybridizations in bonding the B and Ti atoms, respectively, are responsible for the enhanced stability of the Ti n-1B system. The Ti4B and Ti6B clusters are found to be far more stable relative to their corresponding neighbours. The doping of B also brings the decrease of average magnetic moment for most of the clusters. The spin magnetic moments of both host and B-substituted clusters are of Ti 3d characters. © 2010 IOP Publishing Ltd.

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