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Molecular dynamics simulation was used to investigate the mechanical properties of (5, 5), and (10, 10) single-walled nanocoils, as well as (5, 5)@(10, 10) double-walled carbon nanocoils (CNCS). The second reactive empirical bond order potential was employed to model the interaction between carbon atoms. The atomic slip vector and sequential slip vector were used to investigate the structural variations at different strains during the tension process. The yield stress, maximum tensile strength, and Young’s modulus were determined from the tensile stress–strain profiles. The results show that the nanocoils have superelastic characteristics and have a high strength similar to that of carbon nanotube with same chirality.

Understanding the electronic structures and properties of different size CeO 2 nanoparticles is very important for further application in the field of catalysis used in several promising materials. In this study, we have elucidated the electronic analyses of (CeO 2 ) n ( n = 1–5) nanoparticles through first-principle density-functional theory approach. All structures with the global minimal energies are obtained by fire algorithm combining simulated annealing method and then are further re-optimized by DMol 3 program with double numerical atomic basis sets. Two useful analyzed methods (Fukui function and electronic density of state) are calculated to explain the chemical reactivity of different sites for (CeO 2 ) n ( n = 1–5) nanoparticles.

Thermodynamic properties of titanium dioxide (TiO 2 ) n ( n = 1–6) nanoparticles were studied by first-principle molecular dynamics (MD) simulation. The configurations for (TiO 2 ) n ( n = 1–6) nanoparticles with global minimum energies can be initially obtained by MD simulation combined with the fast inertial relaxation engine algorithm. These structures can be further refined by density functional theory simulation. The variation of internal energies and Lindemann criteria with the simulation temperature was used to indicate the occurring of phase change for (TiO 2 ) n ( n = 1–6) nanoparticles. The effect of size and geometry on the thermodynamic properties of TiO 2 nanoparticles was also found.

Understanding material properties of CeO2 nanoparticles of different sizes is very important for its further applications in the field of catalysis used in solid-oxide fuel cells. In this study, the fast inertial relaxation engine (FIRE) algorithm combined with the simulated annealing method was firstly employed to find the structures of (CeO2)n (n = 1–5) with global minimum potential energy. These structures were further refined by the density functional theory (DFT) simulation in order to deeply understand their structural properties.

Understanding the mechanical properties of multilayered metal thin films is very important for their applications in nanoscale devices. Nanoindentation is one of the widely used tools for examining the mechanical properties of metal thin films. In the present study, molecular dynamics simulation was employed to investigate the nanoindentation behavior of a Cu(100)/Cu(110) bilayered thin film. The load-displacement response and the detailed deformation structure of the copper thin film during the nanoindentation were inspected and compared with those of Cu(100) and Cu(110) thin films. It was found that at the indenting stage the maximum indentation load of the bi-layered thin film is lower than that of its ingredients, however, they have nearly the same maximum indentation load. At the retracting stage, the maximum attractive force of the bilayered thin film was found near that of its ingredients but occurred much earlier than the ingredients. The detailed deformation structure of the bilayered thin film was observed to be similar to that of the ingredients and correlated very well with the load-displacement response.

Molecular dynamics simulation was carried out to investigate the behavior of (5,5) and (10,10) armchair carbon nanotubes in water under tensile loading. The water molecules inside a nanoscale tube, unlike inside a bulk tube, have a confined effect. The local density distributions of oxygen and hydrogen atoms inside the carbon nanotubes were calculated to find the confinement effect. Moreover, the mechanical behavior of carbon nanotubes in water was studied under tensile loading. The results show that the Young's modulus of nano-tubes in water remains the same as that in vacuum. However, the tensile stress of nanotube in water is less than that in vacuum.

In recent years, the phonon spectrum has attracted much interest in investigations of electric transfer in nanowires. In this study, molecular dynamics is employed to calculate the phonon characteristics of thinness for 7-1 gold nanowire stretched at room temperature. This study finds that the two major peaks of phonon density of state (DOS) of 7-1 nanowire represent low characteristic frequency shifts to the left, while high characteristic frequency is less significant changed compared with the characteristic frequency in bulk. The high frequency intensity of DOS for 7-1 nanowire is lower than that of low frequency. The low frequency shifts left for large elastic strain during elastic deformation. Moreover, the phonon spectrums of one-atom chain structures formed before the nanowire breaks becomes discrete. The influences of local atomic arrangement and stretch condition on the phonon profile are analyzed in this study.