APPLICATION OF THE NEURAL NETWORKS FOR DEVELOPING NEW PARAMETERIZATION OF THE TERSOFF POTENTIAL FOR CARBON

Penta-graphene (PG) is a 2D carbon allotrope composed of a layer of pentagons having 𝑠𝑝2- and 𝑠𝑝3- bonded carbon atoms. A study carried out in 2018 has shown that the parameterization of the Tersoff potential proposed in 2005 by Ehrhart and Able (T05 potential) performs better than other potentials...

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Main Authors: ANTHONY CHUKWUEMEKA NWACHUKWU, SZYMON WINCZEWSKI
Format: Article
Language:English
Published: Gdańsk University of Technology 2020-10-01
Series:TASK Quarterly
Subjects:
Online Access:https://journal.mostwiedzy.pl/TASKQuarterly/article/view/1655
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author ANTHONY CHUKWUEMEKA NWACHUKWU
SZYMON WINCZEWSKI
author_facet ANTHONY CHUKWUEMEKA NWACHUKWU
SZYMON WINCZEWSKI
author_sort ANTHONY CHUKWUEMEKA NWACHUKWU
collection DOAJ
description Penta-graphene (PG) is a 2D carbon allotrope composed of a layer of pentagons having 𝑠𝑝2- and 𝑠𝑝3- bonded carbon atoms. A study carried out in 2018 has shown that the parameterization of the Tersoff potential proposed in 2005 by Ehrhart and Able (T05 potential) performs better than other potentials available for carbon, being able to reproduce structural and mechanical properties of the PG. In this work, we tried to improve the T05 potential by searching for its parameters giving a better reproduction of the structural and mechanical properties of the PG known from the ab initio calculations. We did this using Molecular Statics (MS) simulations and Neural Network (NN). Our test set consisted of the following structural properties: the lattice parameter 𝑎; the interlayer spacing ℎ; two lengths of C-C bonds, 𝑑1 and 𝑑2 respectively; two valence angles, 𝜃1 and 𝜃2, respectively. We also examined the mechanical properties by calculating three elastic constants, 𝐶11, 𝐶12 and 𝐶66, and two elastic moduli, the Young’s modulus 𝐸 and the Poisson’s ratio 𝜈. We used MS technique to compute the structural and mechanical properties of PG at 𝑇 = 0 K. The Neural Network used is composed of 2 hidden layers, with 20 and 10 nodes for the first and second layer, respectively. We used an Adams optimizer for the NN optimization and the Mean Squared Error as the loss function. We obtained inputs (about 80 000 different sets of potential parameters) for the Molecular Statics simulation by using randomly generated numbers. The outputs from these simulations became the inputs to our Neural Network. The Molecular Statics simulations were done with LAMMPS while the Neural Network and other computations were done with Python, Pytorch, Numpy, Pandas, GNUPLOT and Bash scripts. We obtained a parameterization which has a slightly better accuracy (lower relative errors of the calculated structural and mechanical properties) than the original parameterization.
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spelling doaj.art-c9089e2e1a4442208f7d5caf2bdd027f2022-12-22T00:11:42ZengGdańsk University of TechnologyTASK Quarterly1428-63942020-10-0124410.34808/tq2020/24.4/aAPPLICATION OF THE NEURAL NETWORKS FOR DEVELOPING NEW PARAMETERIZATION OF THE TERSOFF POTENTIAL FOR CARBONANTHONY CHUKWUEMEKA NWACHUKWU0SZYMON WINCZEWSKI1Gdansk University of Technology, Faculty of Applied Physics and MathematicsGdansk University of Technology, Faculty of Applied Physics and Mathematics Penta-graphene (PG) is a 2D carbon allotrope composed of a layer of pentagons having 𝑠𝑝2- and 𝑠𝑝3- bonded carbon atoms. A study carried out in 2018 has shown that the parameterization of the Tersoff potential proposed in 2005 by Ehrhart and Able (T05 potential) performs better than other potentials available for carbon, being able to reproduce structural and mechanical properties of the PG. In this work, we tried to improve the T05 potential by searching for its parameters giving a better reproduction of the structural and mechanical properties of the PG known from the ab initio calculations. We did this using Molecular Statics (MS) simulations and Neural Network (NN). Our test set consisted of the following structural properties: the lattice parameter 𝑎; the interlayer spacing ℎ; two lengths of C-C bonds, 𝑑1 and 𝑑2 respectively; two valence angles, 𝜃1 and 𝜃2, respectively. We also examined the mechanical properties by calculating three elastic constants, 𝐶11, 𝐶12 and 𝐶66, and two elastic moduli, the Young’s modulus 𝐸 and the Poisson’s ratio 𝜈. We used MS technique to compute the structural and mechanical properties of PG at 𝑇 = 0 K. The Neural Network used is composed of 2 hidden layers, with 20 and 10 nodes for the first and second layer, respectively. We used an Adams optimizer for the NN optimization and the Mean Squared Error as the loss function. We obtained inputs (about 80 000 different sets of potential parameters) for the Molecular Statics simulation by using randomly generated numbers. The outputs from these simulations became the inputs to our Neural Network. The Molecular Statics simulations were done with LAMMPS while the Neural Network and other computations were done with Python, Pytorch, Numpy, Pandas, GNUPLOT and Bash scripts. We obtained a parameterization which has a slightly better accuracy (lower relative errors of the calculated structural and mechanical properties) than the original parameterization. https://journal.mostwiedzy.pl/TASKQuarterly/article/view/1655penta-graphenemechanical propertiesmolecular dynamics
spellingShingle ANTHONY CHUKWUEMEKA NWACHUKWU
SZYMON WINCZEWSKI
APPLICATION OF THE NEURAL NETWORKS FOR DEVELOPING NEW PARAMETERIZATION OF THE TERSOFF POTENTIAL FOR CARBON
TASK Quarterly
penta-graphene
mechanical properties
molecular dynamics
title APPLICATION OF THE NEURAL NETWORKS FOR DEVELOPING NEW PARAMETERIZATION OF THE TERSOFF POTENTIAL FOR CARBON
title_full APPLICATION OF THE NEURAL NETWORKS FOR DEVELOPING NEW PARAMETERIZATION OF THE TERSOFF POTENTIAL FOR CARBON
title_fullStr APPLICATION OF THE NEURAL NETWORKS FOR DEVELOPING NEW PARAMETERIZATION OF THE TERSOFF POTENTIAL FOR CARBON
title_full_unstemmed APPLICATION OF THE NEURAL NETWORKS FOR DEVELOPING NEW PARAMETERIZATION OF THE TERSOFF POTENTIAL FOR CARBON
title_short APPLICATION OF THE NEURAL NETWORKS FOR DEVELOPING NEW PARAMETERIZATION OF THE TERSOFF POTENTIAL FOR CARBON
title_sort application of the neural networks for developing new parameterization of the tersoff potential for carbon
topic penta-graphene
mechanical properties
molecular dynamics
url https://journal.mostwiedzy.pl/TASKQuarterly/article/view/1655
work_keys_str_mv AT anthonychukwuemekanwachukwu applicationoftheneuralnetworksfordevelopingnewparameterizationofthetersoffpotentialforcarbon
AT szymonwinczewski applicationoftheneuralnetworksfordevelopingnewparameterizationofthetersoffpotentialforcarbon