The Molecular Dynamics Simulation Of Quasicrystal Structures In Two Dimensions

To simulate the formation of quasicrystals can help people understand their growth mechanism and related properties.In this thesis,we use the molecular dynamics simulation method in two-dimensions,hoping to obtain different quasicrystal structures with suitable potential functions.According to other's work in the molecular dynamics simulation of quasicrystal,we compare a few types of potential functions commonly used in quasicrystals simulation,study the features of each potential function and summarize their suitable systems.We chose the Lennard-Jones-Gauss potential in MD simulations,a kind of potential with two potential wells considering the long-range influence.Based on the work of Engel et al.,we perform a series of molecular dynamics simulations.The decagonal and dodecagonal quasicrystals are obtained,we verify and explain the formation of quasicrystals from the perspective of the diffraction image,radial distribution function and energy.The decagonal quasicrystal possesses more perfect tiling with ten-fold symmetry;The dodecagonal quasicrystal obtained is coincide with an ideal quasicrystal tiling,which has not been reported before.Through the research in this thesis,we conclude that the position and the depth of potential well in double-well potential are the main factors to simulate the quasicrystal.More quasicrystal structures may be obtained in this kind of potential by changing the depth and width of the potential wells.