Geometry optimization is an important part of both computational materials and surface science because it is the path to finding ground state atomic structures and reaction pathways. These properties are used in the estimation of thermodynamic and kinetic properties of molecular and crystal structures. This process is slow at the quantum level of theory because it involves an iterative calculation of forces using quantum chemical codes such as density functional theory (DFT), which are computationally expensive, and which limit the speed of the optimization algorithms. It would be highly advantageous to accelerate this process because then one could either do the same amount of work in less time, or more work in the same time. In this work, we provide a neural network (NN) ensemble based active learning method to accelerate the local geometry optimization for multiple configurations simultaneously. We illustrate the acceleration on several case studies including bare metal surfaces, surfaces with adsorbates, and nudged elastic band (NEB) for two reactions. In all cases the accelerated method requires fewer DFT calculations than the standard method. In addition, we provide an ASE-optimizer Python package to make the usage of the NN ensemble active learning for geometry optimization easier.
Evidence for percolation diffusion of cations and material recovery in disordered pyrochlore from accelerated molecular dynamics simulations
我们使用经典和加速分子动力学模拟来表征空位介导的扩散的阳离子在Gd $_2$ Ti $_2$ O $_7$烧绿石作为一个功能的微秒时间尺度上的无序。我们发现，在低水平的无序材料中，阳离子空位扩散是缓慢的。然而，更高水平的无序允许快速的阳离子扩散，然后还伴随着快速的反位湮灭和阳离子的有序化。因此，阳离子扩散率不是恒定的，而是随着材料重新排序而降低。结果表明，快速阳离子扩散是由反位的渗流网络的存在触发的。这与氧扩散形成鲜明对比，氧扩散显示出随着同一化合物中无序度的增加，离子扩散率平稳增加。无序的阳离子扩散系数的增加也与其他复杂氧化物和无序介质模型的观察相反，这表明无序和质量传输之间存在根本不同的关系。这些结果突出了快速阳离子扩散和无序恢复之间的动态相互作用，并具有重要的意义，了解辐射损伤的演变，烧结和老化，以及扩散的无序氧化物更普遍。
Machine Learning Accelerated Computational Surface-Specific Vibrational Spectroscopy Reveals Oxidation Level of Graphene in Contact with Water
State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, Discipline of Intelligent Instrument and Equipment, Xiamen University（厦门大学化学化工学院物理化学固体表面国家重点实验室）；Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University（厦门大学彭唐沙微纳科学技术研究院）；Institute of Artificial Intelligence, Xiamen University（厦门大学人工智能研究院）
Neural operator accelerated atomistic to continuum concurrent multiscale simulations of viscoelasticity
National Center for Computational Sciences, Oak Ridge National Laboratory（橡树岭国家实验室计算科学国家中心）；Department of Engineering, University of Cambridge（剑桥大学工程系）
Accelerated "on-the-fly" coupled-cluster path-integral molecular dynamics: Impact of nuclear quantum effects on an asymmetric proton
University of Paderborn（帕德博恩大学）；Center for Advanced Systems Understanding (CASUS)（高级系统理解中心）；Helmholtz Zentrum Dresden-Rossendorf（德累斯顿-罗斯多夫亥姆霍兹中心）；Technische Universität Dresden（德累斯顿工业大学）
