Qingshi Zhu

Adsorption energies of molecular oxygen on Au clusters

The adsorption properties of O(2) molecules on anionic, cationic, and neutral Au(n) clusters (n=1-6) are studied using the density functional theory (DFT) with the generalized gradient approximation (GGA), and with the hybrid functional. The results show that the GGA calculations with the PW91 functional systemically overestimate the adsorption energy by 0.2-0.4 eV than the DFT ones with the hybrid functional, resulting in the failure of GGA with the PW91 functional for predicting the adsorption behavior of molecular oxygen on Au clusters. Our DFT calculations with the hybrid functional give the same adsorption behavior of molecular oxygen on Au cluster anions and cations as the experimental measurements. For the neutral Au clusters, the hybrid DFT predicts that only Au(3) and Au(5) clusters can adsorb one O(2) molecule.

Piezoelectricity in ZnO nanowires: A first-principles study

Hexagonal [0001] nonpassivated ZnO nanowires with diameters up to 2.8nm are studied with density functional calculations. The authors find that ZnO nanowires have larger effective piezoelectric constant than bulk ZnO due to their free boundary. For ZnO nanowires with diameters larger than 2.8nm, the effective piezoelectric constant is almost a constant. Surprisingly, the effective piezoelectric constant in small ZnO nanowires does not depend monotonically on the radius due to two competitive effects. Moreover, the quantum confinement effect results in larger band gaps of bare ZnO nanowires compared to that of bulk ZnO.

Electron-phonon coupling in a boron-doped diamond superconductor

The electronic structure, lattice dynamics, and electron-phonon coupling of the boron-doped diamond are investigated using the density-functional supercell method. Our results indicate the boron-doped diamond is a phonon mediated superconductor, confirming previous theoretical conclusions deduced from the calculations employing the virtual-crystal approximation. We show that the optical-phonon modes involving B vibrations play an important role in the electron-phonon coupling. Different from previous theoretical results, our calculated electron-phonon coupling constant is 0.39 and the estimated superconducting transition temperature

Theoretical study of nitric oxide adsorption on Au clusters

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Towards zero discharge of chromium-containing leather waste through improved alkali hydrolysis

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Are fluorinated boron nitride nanotubes n-type semiconductors?

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High resolution vibration-rotation spectrum of the D2O molecule in the region near the 2ν1 + ν2 + ν3 absorption band

for the boron-doped diamond with 2.78% boron content using the Coulomb pseudopotential

Defects-enhanced dissociation of H2 on boron nitride nanotubes

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High resolution spectroscopic study of arsine: 3ν1 and 2ν1+ν3 dyad: The tendency of symmetry reduction

, in excellent agreement with the experimental result.

Half-metallic ferromagnetism in transition-metal encapsulated boron nitride nanotubes

The adsorption properties of NO molecule on anionic, cationic, and neutral Au(n) clusters (n=1-6) are studied using the density functional theory with the generalized gradient approximation, and with the hybrid functional. For anionic and cationic clusters, the charge transfer between the Au clusters and NO molecule and the corresponding weakening and elongation of the N-O bond are essential factors of the adsorption. The neutral Au clusters have also remarkable adsorption ability to NO molecule. The adsorption energies of NO on the cationic clusters are generally greater than those on the neutral and anionic clusters.