Matching conditions in the quasicontinuum method: Removal of the error introduced at the interface between the coarse-grained and fully atomistic region
Matching conditions in the quasicontinuum method: Removal of the error introduced at the interface between the coarse-grained and fully atomistic region
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DOI：
10.1103/physrevb.69.214104
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发表时间：
2004-06
影响因子：
3.7
通讯作者：
T. Shimokawa;T. Shimokawa;T. Shimokawa;J. Mortensen;J. Schiøtz;K. Jacobsen
中科院分区：
文献类型：
--
作者：
T. Shimokawa;T. Shimokawa;T. Shimokawa;J. Mortensen;J. Schiøtz;K. Jacobsen
准连续体方法是一种通过去除缓慢变化应变场区域中的大多数原子来减少原子模拟中自由度的方法。由于在粗粒度区域和所有原子都存在的区域计算原子能量的方法不同，在界面处产生了称为“鬼力”的非物理力。修正可以用来几乎消除鬼力，但修正力是非保守的，破坏了动态模拟中的能量守恒。我们证明，通过在两个空间区域之间引入缓冲层，可以在没有这些问题的情况下表述准连续体方法。该方法适用于面心立方、体心立方和六方密排晶体结构中的短程电位。
The quasicontinuum method is a way of reducing the number of degrees of freedom in an atomistic simulation by removing the majority of the atoms in regions of slowly varying strain fields. Due to the different ways the energy of the atoms is calculated in the coarse-grained regions and the regions where all the atoms are present, unphysical forces called ``ghost forces'' arise at the interfaces. Corrections may be used to almost remove the ghost forces, but the correction forces are nonconservative, ruining energy conservation in dynamic simulations. We show that it is possible to formulate the quasicontinuum method without these problems by introducing a buffer layer between the two regions of space. The method is applicable to short-ranged potentials in the face-centered cubic, body-centered cubic, and hexagonal close-packed crystal structures.