Abstract: In this paper, a molecular dynamics simulations are provided for atomic structure of nanocrystals (1～3nm) by which the lattice parameter of X-ray diffraction, cohesive energy and modulus of elasticity were computed. The results show that the structure of grain and grain boundaries in the same in both nanocrystal and coarse grain materials. The decrease of grain size and the increase volume fraction of grain boundaries lead to a series of different features, the modulus of elasticity of nanocrystalline materials have been found to be much reduced.

Key words: molecular dynamics, nanocrystal, X-ray, modulus of elasticity