Parameterization of classical nonpolarizable force field for hydroxide toward the large‐scale molecular dynamics simulation of cellulose in pre‐cooled alkali/urea aqueous solution

2021 ◽  
pp. 51477
Author(s):  
Yu Chen ◽  
Xiaotong Fu ◽  
Shuxian Yu ◽  
Kun Quan ◽  
Changjun Zhao ◽  
...  
2021 ◽  
Author(s):  
Kai Xu ◽  
Lei Yan ◽  
Bingran You

Force field is a central requirement in molecular dynamics (MD) simulation for accurate description of the potential energy landscape and the time evolution of individual atomic motions. Most energy models are limited by a fundamental tradeoff between accuracy and speed. Although ab initio MD based on density functional theory (DFT) has high accuracy, its high computational cost prevents its use for large-scale and long-timescale simulations. Here, we use Bayesian active learning to construct a Gaussian process model of interatomic forces to describe Pt deposited on Ag(111). An accurate model is obtained within one day of wall time after selecting only 126 atomic environments based on two- and three-body interactions, providing mean absolute errors of 52 and 142 meV/Å for Ag and Pt, respectively. Our work highlights automated and minimalistic training of machine-learning force fields with high fidelity to DFT, which would enable large-scale and long-timescale simulations of alloy surfaces at first-principles accuracy.


2011 ◽  
Vol 116 (1) ◽  
pp. 305-313 ◽  
Author(s):  
Shengting Cui ◽  
Valmor F. de Almeida ◽  
Benjamin P. Hay ◽  
Xianggui Ye ◽  
Bamin Khomami

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 770 ◽  
Author(s):  
Qinghua Chang ◽  
Jingpei Xie ◽  
Aixia Mao ◽  
Wenyan Wang

Large scale Atomic/Molecular dynamic Parallel Simulator (LAMMPS) molecular dynamics simulation software was used to simulate the copper and aluminum atom diffusion and changes of interface during heating and cooling process of copper and aluminum composite panels. The structures of the interface were characterized through scanning electron microscope (SEM), X-ray diffraction (XRD), and transmission electron microscope (TEM), and the mechanical properties were also tested. The simulation results show that the diffusion rate of copper atom is higher than that of aluminum atom, and that the CuAl2 radial distribution function of the interface at 300 K is consistent with that of pure CuAl2 at room temperature. At 930 K, t = 50 ps Cu atoms spread at a distance of approximately four Al lattice constants around the Al layer, and Al atoms spread to about half a lattice constant distance to the Cu layer. The experimental results show that the thickness of the interface in copper–aluminum composite plate is about 1 μm, and only one kind of CuAl2 with tetragonal phase structure is generated in the interface, which corresponds with the result of molecular dynamics simulation.


Sign in / Sign up

Export Citation Format

Share Document