Molecular dynamics simulations on the dynamics of two-dimensional rounded squares

作     者：Zhang-lin Hou Ying Ju Yi-wu Zong Fang-fu Ye Kun Zhao 侯章林;句颖;宗奕吾;叶方富;赵坤

作者机构：Key Laboratory of Systems Bioengineering(Ministry of Education)School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Beijing National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics of Chinese Academy of SciencesInstitute of PhysicsChinese Academy of SciencesBeijing 100190China 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2018年第27卷第8期

页      面：612-618页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.21573159 and 21621004) 

主　　题：molecular dynamics simulation rounded square hoppin gliding collec tive motion 

摘      要：The collective motion of rounded squares with different comer-roundness ζ is studied by molecular dynamlcs （MD） simulation in this work. Three types of translational collective motion pattern are observed, including＇, gliding, hopping and a mixture of gliding and hopping. Quantitatively, the dynamics of each observed ordered phase is characterized by both mean square displacement and van Hove functions for both translation and rotation. The effect of corner-roundness on the dynamics is further studied by comparing the dynamics of the rhombic crystal phases folmed by different comer-.rounded particles at a same surface fraction. The results show that as ζ increases from 0.286 to 0.667, the translational collective motion of particles changes from a gliding-dominant pattern to a hopping-dominant patte;n, whereas the rotational motion pattern is hopping-like and does not change in its type, but the rotational hopping becomes much more frequent as increases （i.e., as particles become more rounded）. A simple geometrical model is proposed to explain the trend of gliding motion observed in MD simulations.