钽酸钾晶体极化性能的从头算分子动力学研究样本

下载后可任意编辑钽酸钾晶体极化性能的从头算分子动力学讨论摘 要分子动力学计算机模拟是讨论复杂的凝聚态系统的有力工具, 这一技术既能得到原子的运动轨迹, 还能像做实验一样作各种观察。对于平衡系统, 能够在一个分子动力学观察内作时间平均来计算一个物理量的统计平均值。对一个非平衡系统过程, 只要发生在一个分子动力学观察时间内(1～10ps)的物理现象也能够用分子动力学计算进行直接模拟。Car、 Parrinello 首次提出的从头计算分子动力学方法有机地结合了密度泛函理论和分子动力学技术, 是当前计算机模拟实验中最先进最重要的方法之一。本文经过使用从头计算分子动力学模拟方法利用 CPMD 程序对钽酸钾( KTaO3) 晶体进行分子动力学模拟, 给出模拟后的晶格图, 并计算出 B 位原子偏离氧八面体中心的距离, 求出自发极化强度, 比较三种材料的自发极化强度大小, 分析自发极化强度的影响因素, 并计算压电常数。关键词: 动力学模拟; 钽酸钾; 极化强度; 压电常数下载后可任意编辑下载后可任意编辑ABSTRACTMolecular dynamics computer simulation is a powerful tool to study complexity of condensed matter systems, This technology can not only get the trajectory of the atom, but also do a variety of observation like to do experiment. For the balance system, the observation of a molecular dynamics observation time average to calculate the statistical average of a physical quantity. For a no-equilibrium system in a molecular dynamics observation period (1～10ps) can also be calculated using molecular dynamics and make direct simulation. Car, Parrinello first proposed comband ab initio molecular dynamics method with the density functional theory and molecular dynamics computer simulations, and this method is most advanced and important in computer simulations. By using ab initio molecular dynamics simulation method and CPMD program make molecular dynamics simulation to KTaO3, display the lattice diagram after simulation. And calculate the distance of B-site atoms deviate from the cente...