Mathiesen Nicolai Rask, Jónsson Hannes, Vegge Tejs, García Lastra Juan Maria
Department of Energy Conversion and Storage , Technical University of Denmark , Fysikvej, 2800 Kgs. Lyngby , Denmark.
Science Institute and Faculty of Physical Sciences , University of Iceland , 107 Reykjavík , Iceland.
J Chem Theory Comput. 2019 May 14;15(5):3215-3222. doi: 10.1021/acs.jctc.8b01229. Epub 2019 Apr 3.
Many activated processes in materials science, physics, and chemistry, e.g. diffusion processes, have initial and final states related by symmetry. Identification of minimum energy paths in such systems with methods such as nudged elastic band (NEB) can gain substantial speed up if the symmetry is exploited. The identification of minimum energy paths and transition states for such processes constitute a large fraction of the CPU-usage within computational materials science; much of which is in essence redundant due to symmetry. Paths with a reflection symmetry can be calculated using about half the computational resources, and the activation energy can, for some transitions, be estimated with high precision with a speed up factor equal to the number of images used in a standard NEB calculation. We present the formal properties required for a system to guarantee a reflection symmetric minimum energy path and an implementation to prepare and effectively speed up nudged elastic band calculations through symmetry considerations. Five examples are given to show the versatility and effectiveness of the method and to validate the implementation. The method is implemented in the open source package Atomic Simulation Environment (ASE) and contains internal methods to identify symmetry relations between the given end point configurations.
材料科学、物理学和化学中的许多活化过程，例如扩散过程，其初始态和终态通过对称性相关联。如果利用对称性，使用诸如推挤弹性带（NEB）等方法识别此类系统中的最小能量路径可显著加快速度。识别此类过程的最小能量路径和过渡态在计算材料科学中占CPU使用量的很大一部分；由于对称性，其中许多本质上是冗余的。具有反射对称性的路径可以使用大约一半的计算资源来计算，并且对于某些跃迁，活化能可以以等于标准NEB计算中使用的图像数量的加速因子高精度估计。我们给出了系统保证反射对称最小能量路径所需的形式性质，以及通过对称性考虑来准备和有效加速推挤弹性带计算的实现方法。给出了五个例子来说明该方法的通用性和有效性，并验证实现。该方法在开源软件包原子模拟环境（ASE）中实现，并包含识别给定端点构型之间对称关系的内部方法。
