Anisotropy of crystal-melt interfacial free energy of silicon by simulation (2008)
Apte, Pankaj A., Zeng, Xiao Cheng
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...
Search for lowest-energy structure of Zintl dianion Si122-, Ge122-, and Sn122- (2008)
Shao, Nan, Bulusu, Satya, Zeng, Xiao Cheng
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...
Yoo, Soohaeng, Shao, N., Zeng, Xiao Cheng
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...
An, Wei, Shao, Nan, Bulusu, Satya, Zeng, Xiao Cheng
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...
Li, Guangping, Sabirianov, R. F., Lu, Jing, Zeng, Xiao Cheng, Mei, W. N.
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...
Pal, R., Cui, Li-Feng, Bulusu, S., Zhai, Hua-Jin, Wang, Lai-Sheng, Zeng, Xiao Cheng
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)....
Structure and thermophysical properties of single-wall Si nanotubes (2007)
Wang, Xinwei, Huang, Zhen, Wang, Tao, Tang, Yuk Wai, Zeng, Xiao Cheng
In this work, molecular dynamics (MD) simulation based on the environment-dependent interatomic potential is carried out to explore the structure, atomic energy distribution, and thermophysical...
Yan, Binghai, Zeng, Xiao Cheng, Wu, Jian, Gu, Bing-Lin, Duan, Wenghui
First-principles calculations of crystalline silicon nanotubes (SiNTs) show that nonuniformity in wall thickness can cause sizable variation in the band gap as well as notable shift in the optical...
Thermal stability of nanostructurally stabilized zirconium oxide (2007)
Namavar, Fereydoon, Wang, Gonghua, Cheung, Chin Li, Sabirianov, Renat F., Zeng, Xiao Cheng, Mei, Wai Ning, ...
Nanostructurally stabilized zirconium oxide (NSZ) hard transparent films were produced without chemical stabilizers by the ion beam assisted deposition technique (IBAD). A transmission electron...
We have computed the energies of adsorption of molecular hydrogen on a number of molecular linkers in metal-organic framework solid materials using density functional theory (DFT) and ab initio...
Exohedral silicon fullerenes: SiNPtN/2 (20≤N≤60) (2007)
Pei, Yong, Gao, Yi, Zeng, Xiao Cheng
Using density functional theory method we show that hollow silicon fullerene cages, SiN(20≤N≤60), can be fully stabilized by exohedrally coated platinum atoms (PtN/2), denoted as SiNPtN/2. The...
Hydrogen storage in pillared Li-dispersed boron carbide nanotubes (2007)
Wu, Xiaojun, Gao, Yi, Zeng, Xiao Cheng
Ab initio density-functional theory study suggests that pillared Li-dispersed boron carbide nanotubes is capable of storing hydrogen with a mass density higher than 6.0 weight% and a volumetric...
Yasuoka, Kenji, Zeng, Xiao Cheng
A molecular dynamics simulation of vapor phase nucleation has been performed with 40 000 Lennard-Jones particles for the target gas and 0-160 000 particles for the carrier gas. Three carrier gas...
Doping Golden Buckyballs: Cu@Au16- and Cu@Au17- Cluster Anions (2007)
Wang, Lei-Ming, Bulusu, Satya, Zhai, Hua-Jin, Zeng, Xiao Cheng, Wang, Lai-Sheng
The discovery of the unique catalytic effects of gold nanoparticles on oxide substrates[1] has stimulated a flurry of research into the structures and properties of free gold nanoclusters, which may...
Hydrogen storage in pillared Li-dispersed boron carbide nanotubes (2007)
Wu, XiaoJun, Gao, Yi, Zeng, Xiao Cheng
Ab initio density-functional theory study suggests that pillared Li-dispersed boron carbide nanotubes is capable of storing hydrogen with a mass density higher than 6.0 weight% and a volumetric...
Correlation effects and electronic structure of Gd@C60 (2007)
Sabirianov, R. F., Mei, W. N., Lu, Jing, Gao, Yi, Zeng, Xiao Cheng, Bolskar, R. D., ...
We have investigated the electronic structure of Gd@C60 using ab initio calculations, photoemission and resonant photoemission (constant initial state spectroscopy). In comparing our calculations...
Multiwalled ice helixes and ice nanotubes (2006)
Bai, Jaeil, Wang, Jun, Zeng, Xiao Cheng
We report six phases of high-density nano-ice predicted to form within carbon nanotubes (CNTs) at high pressure. High-density nano-ice self-assembled within smaller-diameter CNT (17,0) exhibits a...
Structures and relative stability of neutral gold clusters: Aun (n=15-19) (2006)
Bulusu, Satya, Zeng, Xiao Cheng
We performed a global-minimum search for low-lying neutral clusters (Aun) in the size range of n=15-19 by means of basin-hopping method coupled with density functional theory calculation. Leading...
Homogeneous nucleation at high supersaturation of vapor and heterogeneous nucleation on microscopic wettable particles are studied on the basis of Lennard-Jones model system. A hybrid classical...
Diestler, Dennis J., Zhou, H., Feng, Ruqiang, Zeng, Xiao Cheng
A treatment of multiscale quasistatic processes that combines an atomistic description of microscopic heterogeneous ("near") regions of a material with a coarse-grained (quasicontinuum) description...
Adsorption of transition-metal atoms on boron nitride nanotube: A density-functional study (2006)
Adsorption of transition atoms on a (8,0) zigzag single-walled boron nitride (BN) nanotube has been investigated using density-functional theory methods. Main focuses have been placed on...
Adsorption of hydrogen molecules on the platinum-doped boron nitride nanotubes (2006)
Wu, Xiaojun, Yang, J.L., Zeng, Xiao Cheng
Adsorption of hydrogen molecules on platinum-doped single-walled zigzag (8,0) boron nitride (BN) nanotube is investigated using the density-functional theory. The Pt atom tends to occupy the axial...
Molecular simulations of solid-liquid interfacial tension of silicon (2006)
Tang, Yuk Wai, Wang, Jun, Zeng, Xiao Cheng
Silicon is an important semiconductor for manufacturing of microelectronic chips used in computers and other electronic devices. During the manufacturing process, liquid silicon is being solidified...
Evidence of hollow golden cages (2006)
Bulusu, Satya S., Li, Xi, Wang, Lai-Sheng, Zeng, Xiao Cheng
The fullerenes are the first "free-standing" elemental hollow cages identified by spectroscopy experiments and synthesized in the bulk. Here, we report experimental and theoretical evidence of hollow...
Evidence of hollow golden cages: Supplementary Materials and Supporting Information (2006)
Bulusu, Satya S., Li, Xi, Wang, Lai-Sheng, Zeng, Xiao Cheng
Figures 3A-3D: Simulated anion photoelectron spectra [based on the density-functional theory (DFT) calculation with the PBEPBE/LANL2DZ functional and basis set] for all of the candidate lowest-energy...
We performed a constrained search for the geometries of low-lying neutral germanium clusters GeN in the size range of 21≤N≤29. The basin-hopping global optimization method is employed for the...
Yoo, Soohaeng, Shao, N., Koehler, C., Fraunhaum, T., Zeng, Xiao Cheng
We have performed unconstrained search for low-lying structures of medium-sized silicon clusters Si31-Si40 and Si45, by means of the minimum-hopping global optimization method coupled with a...
An, Wei, Bulusu, Satya, Gao, Yi, Zeng, Xiao Cheng
High-level ab initio molecular-orbital methods have been employed to determine the relative stability among four neutral and anionic B20 isomers, particularly the double-ring tubular isomer versus...
Yoo, Soohaeng, Zeng, Xiao Cheng
Structures and relative stability of four families of low-lying silicon clusters in the size range of Sin(n=21-30) are studied, wherein two families of the clusters show prolate structures while the...
Electronic structure and vibrational spectra of C2B10-based clusters and films (2006)
Park, Kyungwha, Pederson, M. R., Boyer, L. L., Mei, Wai-Ning, Sabirianov, Renat F., Zeng, Xiao Cheng, ...
The electronic structure, total energy, and vibrational properties of C2B10H12 (carborane)molecules and C2B10 clusters formed when the hydrogen atoms are removed from carborane molecules are studied...
M4@Si28 (M=Al,Ga) Metal-encapsulated tetrahedral silicon fullerene (2005)
It is known that silicon fullerenes cannot maintain perfect cage structures like carbon fullerenes. Previous density-functional theory calculations have shown that even with encapsulated species,...
Koishi, Takahiro, Yasuoka, Kenji, Ebisuzaki, Toshikazu, Yoo, S., Zeng, Xiao Cheng
We performed large-scale molecular-dynamics simulation of nanoscale hydrophobic interaction manifested by the formation of nanobubble between nanometer-sized hydrophobic clusters at constrained...
Yoo, Soohaeng, Zeng, Xiao Cheng
It has been established from experiments that stable medium-sized ionic clusters Si15-Si20 are prolate in shape. Density-functional theories (DFTs) also predict that nearly all low-lying neutral...
Zhou, H., Feng, Ruqiang, Diestler, Dennis J., Zeng, Xiao Cheng
A new treatment of quasistatic (reversible) multiscale processes in heterogeneous materials at nonzero temperature is presented. The system is coarse grained by means of a finite-element mesh. The...
Melting temperature of ice Ih calculated from coexisting solid-liquid phases (2005)
Wang, J., Yoo, S., Bai, Jaeil, Morris, James R., Zeng, Xiao Cheng
The purpose of this paper is twofold: (1) to compute the melting temperature (Tm) of ice Ih with both TIP4P and TIP5P models by using the two-phase coexistence method and to compare with previously...
Ab initio calculation of bowl, cage, and ring isomers of C20 and C20- (2005)
An, Wei, Gao, Yi, Bulusu, Satya, Zeng, Xiao Cheng
High-level ab initio calculations have been carried out to reexamine relative stability of bowl, cage, and ring isomers of C20 and C20-. The total electronic energies of the three isomers show...
Parra, Ruben D., Bulusu, Satya, Zeng, Xiao Cheng
Cooperative effects in two-dimensional cyclic networks containing intermolecular three-centered hydrogen bonding interactions of the type H1AH2 are investigated by means of ab intio molecular...
Search for global minimum geometries for medium sized germanium clusters: Ge12-Ge20 (2005)
Bulusu, S., Yoo, S., Zeng, Xiao Cheng
We have performed an unbiased search for the global minimum geometries of small-to-medium sized germanium clusters Gen (12≤n≤18) as well as a biased search (using seeding method) for Gen...
Diestler, Dennis J., Zeng, Xiao Cheng
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...
Nanoscale Hydrophobic Interaction and Nanobubble Nucleation (2004)
Koishi, T., Yoo, S., Yasuoka, K., Zeng, Xiao Cheng, Narumi, T., Susukita, R., ...
We report large-scale atomistic simulation of midrange nanoscale hydrophobic interaction, manifested by the nucleation of nanobubble between nanometer-sized hydrophobes at constrained equilibrium....
Hybrid atomistic-coarse-grained treatment of thin-film lubrication. II (2004)
Diestler, Dennis J., Zeng, Xiao Cheng
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...
Koyama, Yuji, Tanaka, Hideki, Gao, Guangtu, Zeng, Xiao Cheng
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...
Zeng, Xiao Cheng, Lei, Y.A., Pan, B.
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...
Hybrid atomistic-coarse-grained treatment of thin-film lubrication. I (2004)
Diestler, Dennis J., Feng, Ruqiang, Zeng, Xiao Cheng
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...
The melting lines of model silicon calculated from coexisting solid-liquid phases (2004)
Yoo, S., Zeng, Xiao Cheng, Morris, James R.
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...
Warshavsky, V.B., Zeng, Xiao Cheng
The effect of a uniform electric field on the bulk and interfacial properties of a model dipolar fluid is investigated by using a modified mean-field density functional theory. Particular attention...
Coarse-graining description of solid systems at nonzero temperature (2003)
Diestler, Dennis J., Feng, Ruqiang, Zeng, Xiao Cheng
The quasicontinuum (QC) technique, in which the atomic lattice of a solid is coarse-grained by overlaying it with a finite-element mesh, has been employed previously to treat the quasistatic...
Effect of polarizability of halide anions on the ionic salvation in water clusters (2003)
Yoo, S., Lei, Y.A., Zeng, Xiao Cheng
Molecular dynamics simulation has been performed to study the effect of the polarizabilities of model anions on the ionic solvation in water clusters. The primary focus is given to the surface versus...
Global geometry optimization of silicon clusters described by three empirical potentials (2003)
The "basic-hopping" global optimization technique developed by Wales and Doye is employed to study the global minima of silicon clusters Sin (3
Warshavsky, V.B., Zeng, Xiao Cheng
We have studied the bulk and interfacial properties of a dipolar-quadrupolar fluid based on an extended modified mean-field density-functional theory. Effects of a uniform electric field on the bulk...
Ab initio studies of quasi-one-dimensional pentagon and hexagon ice nanotubes (2003)
Bai, Jaeil, Parra, R.D., Zeng, Xiao Cheng, Tanaka, H., Koga, K., ...
Ab initio plane-wave total-energy calcuation is carried out to study the relative stability of the quasi-one-dimensional (Q1D) pentagon and hexagon ice nanotubes. Electronic structure calculations...
Zhu, Xiaolei, Zeng, Xiao Cheng
Ab initio all-electron molecular-orbital calculations have been carried out to study the structure and relative stability of small silicon clusters (Sin , n=7 - 11). A number of low-energy geometric...
Cooperative effects in one-dimensional chains of three-center hydrogen bonding interactions (2003)
Parra, Ruben D., Bulusu, Satya, Zeng, Xiao Cheng
Cooperative effects in a one-dimensional network of intermolecular bifurcated hydrogen bonding interactions are investigated by means of ab initio calculations. The trans-trans conformation of the...
Monte Carlo simulation of vapor-liquid binodal of water (2002)
Among many popular potential models of water, the nonpolarizable four-site TIP4P potential is one of the more widely used. Recently, two new potential models of water on the basis of the TIP4P...
Warshavsky, V.B., Zeng, Xiao Cheng
The effect of a uniform electric field on interfacial properties of dipolar-quadrupolar fluids is investigated by using the density-functional theory. As in the case of purely dipolar fluids the...
Bulk and interfacial properties of quadrupolar fluids (2002)
Warshavsky, V.B., Zeng, Xiao Cheng
We extend Teixeira and Telo da Gama's density-functional approach [J. Phys.: Condens. Matter 3, 111 (1991)] to study the vapor-liquid phase equilibria and planar interfacial properties of quadrupolar...
A hybrid thermodynamic and density-functional theory for heterogeneous nucleation on mesoscopic wettable particles is developed. The nonlocal density-functional theory (DFT) is on basis of the...
Yoo, S., Oh, K.J., Zeng, Xiao Cheng
Gibbs free energy of ij-cluster formation ΔGij is obtained via the relation nij=Ne-ΔGij /kBT, where N is the number of molecules in the system, T is temperature, and kB is the Boltzmann constant....
Parra, Ruben D., Gong, Bing, Zeng, Xiao Cheng
High level ab initio calculations have been carried out on a number of intramolecular two- and three-center H-bonding structures containing the amide motif, NHC=O. These structures serve as model...
Parra, Ruben D., Furukawa, Makoto, Gong, Bing, Zeng, Xiao Cheng
High level ab initio calculations are carried out on diacetamide-X (DA-X) dimers, X=HCN, CH3OH. The dimers are used as model systems to investigate the energetics and cooperative phenomomena in...
Kholmurodov, K.T., Yasuoka, K., Zeng, Xiao Cheng
Molecular dynamics simulations of nucleation of a supersaturated Lennard-Jones vapor in slit nanopores are carried out. In this study we extend a previous work [K. Yasuoka, G. T. Gao, and X. C. Zeng,...
Nucleation of Water and Methanol Droplets on Cations and Anions: The Sign Preference (2001)
Oh, K.J., Gao, G.T., Zeng, Xiao Cheng
The barrier height to cation- and anion-induced nucleation to produce water and methanol droplets are calculated by means of an umbrella-sampling Monte Carlo method. The computer simulation...
Carrier gases are used in most nucleation experiments for releasing the latent heat generated during vapor condensation. In the analysis of experimental data it is often assumed that the carrier gas...
Effects of external electric field on the interfacial properties of weakly dipolar fluid (2001)
Warshavsky, V.B., Bykov, T.V., Zeng, Xiao Cheng
In the framework of modified mean-field density-functional theory, effects of a uniform electric field on the interfacial properties of a model dipolar fluid [Teixeira and Telo da Gama, J. Phys.:...
Nonlinear effects of physisorption on static friction (2000)
Gao, G.T., Zeng, Xiao Cheng, Diestler, Dennis J.
The effects of a physisorbed film on the force of static friction in a model contact (monatomic adsorbate confined between plane-parallel walls) were investigated by Monte Carlo simulation. At fixed...
Ice nanotube: What does the unit cell look like? (2000)
Koga, Kenichiro, Parra, Ruben D., Tanaka, Hideki, Zeng, Xiao Cheng
It is discovered that for an n-gonal ice nanotube built from stacking a single type of n-gonal rings of water, the unit cell consists of two stacked n-gonal rings. In one ring the O-H bonds of water...
Gao, G.T., Zeng, Xiao Cheng, Tanaka, Hideki
We report computer simulation results of free energies of proton-disordered hexagonal ice and liquid water at atmospheric pressure with the 4-site transferable intermolecular potential model of...
Freezing transition of a strongly dipolar simple fluid (2000)
The freezing transition of a strongly dipolar Lennard-Jones fluid is investigated using Monte Carlo simulation. It is found that the system undergoes a ferroelectric liquid-to-solid transition when...
Molecular dynamics simulation of supersaturated vapor nucleation in slit pore (2000)
Yasuoka, K., Gao, G.T., Zeng, Xiao Cheng
Molecular dynamics simulations of nucleation of Lennard-Jones vapor confined in a slit pore have been performed. The walls of the slit pore are structureless walls; each wall interacts with vapor...
A small-system grand canonical ensemble Monte Carlo method is developed to evaluate cluster size distribution and barrier to the nucleation in a supersaturated Lennard-Jones vapor. The theoretical...
A patching model for surface tension of spherical droplet and Tolman length. II (1999)
In the framework of density functional theory (DFT), two patching models for the density profile of spherical liquid droplet are developed. The patching is based on analytical expressions of the...
Imaging point defects in a liquid environment: A model AFM study (1999)
Kago, Kenichiro, Zeng, Xiao Cheng
Effects of the liquid on atomic force microscopy (AFM) imaging are examined for a model system consisting of a hexagonal flake of seven Lennard-Jones (LJ) atoms as a multiatom tip, a monolayer of LJ...
Confined water in hydrophobic nanopores: Dynamics of freezing into bilayer ice (1999)
Slovak, Jan, Kago, Kenichiro, Tanaka, Hideki, Zeng, Xiao Cheng
Molecular dynamics simulations for a thin film of water confined to a slit nanopore are performed in order to investigate the dynamic process of crystallization of the system. The system upon...
A patching model for surface tension and the Tolman length (1999)
In the framework of density functional theory (DFT), a patching model for the density profile of the liquid-vapor interface is developed. The patching is based on analytical expressions of the...
Parra, Ruben D., Zeng, Xiao Cheng
Ab initio calculations are used to provide information on the mixed dimers and cyclic trimers of the methanol-trifluoromethanol system. In order to better understand the systems, the monomers and...
Molecular dynamics study of a phase-separating fluid mixture under shear flow (1999)
Yamamoto, Ryoichi, Zeng, Xiao Cheng
Molecular dynamics simulation is carried out to study domain structures and rheological properties of a two-dimensional phase-separating binary fluid mixture under shear flow. In the early stage of...
Formation free energy of clusters in vapor-liquid nucleation: A Monte Carlo simulation study (1999)
The formation free energy of clusters in a supersaturated vapor is obtained by a constrained Monte Carlo technique. A key feature of this approach is to set an upper limit to the size of cluster....
Koga, Kenichiro, Zeng, Xiao Cheng
Nucleation free-energy barrier height and size of the critical nucleus are expanded in powers of the chemical potential difference between the supersatur