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Articles 1 - 8 of 8
Full-Text Articles in Physical Sciences and Mathematics
An Extension Of The Quasicontinuum Treatment Of Multiscale Solid Systems To Nonzero Temperature, Dennis J. Diestler, Z.-B. Wu, Xiao Cheng Zeng
An Extension Of The Quasicontinuum Treatment Of Multiscale Solid Systems To Nonzero Temperature, Dennis J. Diestler, Z.-B. Wu, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
Covering the solid lattice with a finite-element mesh produces a coarse-grained system of mesh nodes as pseudoatoms interacting through an effective potential energy that depends implicitly on the thermodynamic state. Use of the pseudoatomic Hamiltonian in a Monte Carlo simulation of the two-dimensional Lennard-Jones crystal yields equilibrium thermomechanical properties (e.g., isotropic stress) in excellent agreement with “exact” fully atomistic results.
Nanoscale Hydrophobic Interaction And Nanobubble Nucleation, T. Koishi, S. Yoo, K. Yasuoka, Xiao Cheng Zeng, T. Narumi, R. Susukita, A. Kawai, H. Furusawa, A. Suenaga, N. Okimoto, N. Futatsugi, T. Ebisuzaki
Nanoscale Hydrophobic Interaction And Nanobubble Nucleation, T. Koishi, S. Yoo, K. Yasuoka, Xiao Cheng Zeng, T. Narumi, R. Susukita, A. Kawai, H. Furusawa, A. Suenaga, N. Okimoto, N. Futatsugi, T. Ebisuzaki
Xiao Cheng Zeng Publications
We report large-scale atomistic simulation of midrange nanoscale hydrophobic interaction, manifested by the nucleation of nanobubble between nanometer-sized hydrophobes at constrained equilibrium. When the length scale of the hydrophobes is greater than 2 nm, the nanobubble formation shows hysteresis behavior resembling the first-order transition. Calculation of the potential of mean force versus interhydrophobe distance provides a quantitative measure of the strength of the nanoscale hydrophobic interaction.
Hybrid Atomistic-Coarse-Grained Treatment Of Thin-Film Lubrication. Ii, Z.-B. Wu, Dennis J. Diestler, Xiao Cheng Zeng
Hybrid Atomistic-Coarse-Grained Treatment Of Thin-Film Lubrication. Ii, Z.-B. Wu, Dennis J. Diestler, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
A new hybrid atomistic-coarse-grained (HACG) treatment of reversible processes in multiple-scale systems involving fluid-solid interfaces was tested through isothermal-isobaric Monte Carlo simulations of the quasistatic shearing of a model two-dimensional lubricated contact comprising two planar Lennard-Jones solid substrates that sandwich a softer Lennard-Jones film. Shear-stress profiles (plots of shear stress Tyx versus lateral displacement of the substrates) obtained by the HACG technique, which combines an atomistic description of the interfacial region with a continuum description of regions well removed from the interface, are compared with “exact” profiles (obtained by treating the whole system at the atomic scale) for a …
Melting Points And Thermal Expansivities Of Proton-Disordered Hexagonal Ice With Several Model Potentials, Yuji Koyama, Hideki Tanaka, Guangtu Gao, Xiao Cheng Zeng
Melting Points And Thermal Expansivities Of Proton-Disordered Hexagonal Ice With Several Model Potentials, Yuji Koyama, Hideki Tanaka, Guangtu Gao, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
A method of free energy calculation is proposed, which enables to cover a wide range of pressure and temperature. The free energies of proton-disordered hexagonal ice (ice Ih) and liquid water are calculated for the TIP4P [J. Chem. Phys. 79, 926 (1983)] model and the TIP5P @J. Chem. Phys. 112, 8910 (2000) model. From the calculated free energy curves, we determine the melting point of the proton-disordered hexagonal ice at 0.1 MPa (atmospheric pressure), 50 MPa, 100 MPa, and 200 MPa. The melting temperatures at atmospheric pressure for the TIP4P ice and the TIP5P ice are found to be about …
Structures And Stability Of Medium Silicon Clusters. Ii. Ab Initio Molecular Orbital Calculations Of Si12–Si20, X.-L. Zhu, Xiao Cheng Zeng, Y.A. Lei, B. Pan
Structures And Stability Of Medium Silicon Clusters. Ii. Ab Initio Molecular Orbital Calculations Of Si12–Si20, X.-L. Zhu, Xiao Cheng Zeng, Y.A. Lei, B. Pan
Xiao Cheng Zeng Publications
Ab initio all-electron molecular-orbital calculations are carried out to study the structures and relative stability of low-energy silicon clusters (Sin , n=12– 20). Selected geometric isomers include those predicted by Ho et al. [Nature (London) 392, 582 (1998)] based on an unbiased search with tight-binding/genetic algorithm, as well as those found by Rata et al. [Phys. Rev. Lett. 85, 546 (2000)] based on density-functional tight-binding/single-parent evolution algorithm. These geometric isomers are optimized at the Møller–Plesset (MP2) MP2/6-31G(d) level. The single-point energy at the coupled-cluster single and double substitutions (including triple excitations) [CCSD(T)] CCSD(T)/6-31G(d …
Hybrid Atomistic-Coarse-Grained Treatment Of Thin-Film Lubrication. I, Z.-B. Wu, Dennis J. Diestler, Ruqiang Feng, Xiao Cheng Zeng
Hybrid Atomistic-Coarse-Grained Treatment Of Thin-Film Lubrication. I, Z.-B. Wu, Dennis J. Diestler, Ruqiang Feng, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
A technique that melds an atomistic description of the interfacial region with a coarse-grained description of the far regions of the solid substrates is presented and applied to a two-dimensional model contact consisting of planar solid substrates separated by a monolayer fluid film. The hybrid method yields results in excellent agreement with the “exact” (i.e., fully atomistic) results. The importance of a proper accounting for the elastic response of the substrates, which is reliably and efficiently accomplished through coarse-graining of the far regions, is demonstrated.
The Melting Lines Of Model Silicon Calculated From Coexisting Solid–Liquid Phases, S. Yoo, Xiao Cheng Zeng, James R. Morris
The Melting Lines Of Model Silicon Calculated From Coexisting Solid–Liquid Phases, S. Yoo, Xiao Cheng Zeng, James R. Morris
Xiao Cheng Zeng Publications
The melting line is an important thermodynamic property of materials and can be calculated via computer simulation, given the intermolecular potential for the materials. Conventionally, the free-energy method has been mainly employed to calculate the melting line. Alternatives to the free-energy method for calculating the melting line include simulation of the solid-liquid coexistence and nonequilibrium molecular dynamics (MD) method. Recently, one of us (Morris) and Song reported a detailed simulation procedure to calculate the melting line of the Lennard-Jones system. Specifically, the MD simulation consists of a preparation run and a production run. In the preparation run, the liquid and …
Metallic Single-Walled Silicon Nanotubes, Jaeil Bai, Xiao Cheng Zeng, Hideki Tanaka, J. Y. Zeng
Metallic Single-Walled Silicon Nanotubes, Jaeil Bai, Xiao Cheng Zeng, Hideki Tanaka, J. Y. Zeng
Xiao Cheng Zeng Publications
Atomistic computer-simulation evidences are presented for the
possible existence of one-dimensional silicon nanostructures: the
square, pentagonal, and hexagonal single-walled silicon nanotubes
(SWSNTs). The local geometric structure of the SWSNTs
differs from the local tetrahedral structure of cubic diamond
silicon, although the coordination number of atoms of the SWSNTs
is still fourfold. Ab initio calculations show that the SWSNTs
are locally stable in vacuum and have zero band gap, suggesting
that the SWSNTs are possibly metals rather than wide-gap
semiconductors.