Reed Evan J, Fried Laurence E, Joannopoulos J D
Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Phys Rev Lett. 2003 Jun 13;90(23):235503. doi: 10.1103/PhysRevLett.90.235503.
A new multiscale simulation method is formulated for the study of shocked materials. The method combines molecular dynamics and the Euler equations for compressible flow. Treatment of the difficult problem of the spontaneous formation of multiple shock waves due to material instabilities is enabled with this approach. The method allows the molecular dynamics simulation of the system under dynamical shock conditions for orders of magnitude longer time periods than is possible using the popular nonequilibrium molecular dynamics approach. An example calculation is given for a model potential for silicon in which a computational speedup of 10(5) is demonstrated. Results of these simulations are consistent with the recent experimental observation of an anomalously large elastic precursor on the nanosecond time scale.
为研究冲击材料，制定了一种新的多尺度模拟方法。该方法将分子动力学与可压缩流的欧拉方程相结合。这种方法能够处理由于材料不稳定性而自发形成多个冲击波这一难题。与常用的非平衡分子动力学方法相比，该方法能使系统在动态冲击条件下进行分子动力学模拟的时间长度延长几个数量级。针对硅的模型势给出了一个示例计算，其中展示了10(5) 的计算加速比。这些模拟结果与近期在纳秒时间尺度上对异常大弹性前驱波的实验观测结果一致。
