中文摘要：

针对描述金刚石原子间作用力的Tersoff作用势,建立了对应的各向同性非平衡态分子动力学外加力场模型,并采用这种模型模拟了金刚石的导热系数.模拟结果显示：在施加外加扰动力场后,沿力场方向的热流迅速增大并收敛;外加力场越大,相应力场作用下的导热系数的模拟结果越小,金刚石导热系数与外加力场大小呈二次衰减指数关系.与平衡态分子动力学模拟相比,各向同性非平衡分子动力学方法可节省计算机模拟时间约80%;而且对于三维结构,2种方法的模拟结果较为一致,但2种模拟结果均小于实验值,这主要是由描述原子间作用力的Ter-soff作用势的非谐性所致.

英文摘要：

The external force field model for Tersoff potential in the homogeneous non-equilibrium molecular dynamics（HNEMD） simulation of diamond is set up,and the thermal conductivity of diamond is simulated by using this model.It is demonstrated that the heat flux along the direction of external force field increases rapidly and converges when the system is exposed to an external force field.The corresponding thermal conductivity of diamond decreases in a double-exponential decay fashion with the increase of external force field. Compared with equilibrium molecular dynamics（EMD） method,HNEMD simulation can save 80% of the computer CPU time,and for three dimensional structure,the results of both methods agree reasonably well with each other.The simulated thermal conductivity of diamond is lower than that from experimental measurement,which is mainly due to the anharmonicity of Tersoff potential charactering interatomic force.