分子动力学模拟纳米晶体银的结构和性能

摘要

This paper provides a molecular dynamics simulation of nanocrystal of silver using a many-body potential in the frame-work of the Local-Density Approximation(LDA) and Second-Moment Approximation(SMA) to the tight-binding theory.In order to obtain the necessary parameters,we fit the total energy obtained fromm augmented-plane-wave calculations as a function of volume.We apply this scheme to calculate the equilibrium lattice constants,binding energy,free energy,relaxed surface energy,bulk modules,elastic constants and melting temperature.To cheak the accuracy of this method we evaluate structural energies,elasticenergy,and melting temperature etc.Our results are in more agreement with experiments than other methods.%通过分子动力学方法，采用以局域密度（LDA）近似和二阶动量矩（SMA）近似为基础的多体势函数，模拟了纳米面心立方晶体银的结构，对模拟的结果进了不同尺寸的纳米晶体的能量分布，弹性常数，表面能及熔点等计算，并与相应的实验结果进行了比较，结果表明采用此多体势函数模拟纳米晶体的结构和性能，比用其它势函数更精确，与实验结果更吻合。