scholarly journals Bond order redefinition needed to reduce inherent noise in molecular dynamics simulations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ibnu Syuhada ◽  
Nikodemus Umbu Janga Hauwali ◽  
Ahmad Rosikhin ◽  
Euis Sustini ◽  
Fatimah Arofiati Noor ◽  
...  

AbstractIn this work, we present the bond order redefinition needed to reduce the inherent noise in order to enhance the accuracy of molecular dynamics simulations. We propose defining the bond order as a fraction of energy distribution. It happens due to the character of the material in nature, which tries to maintain its environment. To show the necessity, we developed a factory empirical interatomic potential (FEIP) for carbon that implements the redefinition with a short-range interaction approach. FEIP has been shown to enhance the accuracy of the calculation of lattice constants, cohesive energy, elastic properties, and phonons compared to experimental data, and can even be compared to other potentials with the long-range interaction approach. The enhancements due to FEIP can reduce the inherent noise, then provide a better prediction of the energy based on the behaviour of the atomic environment. FEIP can also transform simple two-body interactions into many-body interactions, which is useful for enhancing accuracy. Due to implementing the bond order redefinition, FEIP offers faster calculations than other complex interatomic potentials.

2014 ◽  
Vol 16 (27) ◽  
pp. 14150-14160 ◽  
Author(s):  
Anastasia Gulenko ◽  
Olivier Masson ◽  
Abid Berghout ◽  
David Hamani ◽  
Philippe Thomas

This article derives the interatomic potential for the TeO2 system and presents the first results of molecular dynamics simulations of the pure TeO2 structure.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4326
Author(s):  
Pawel Goj ◽  
Aleksandra Wajda ◽  
Pawel Stoch

Iron-phosphate glasses, due to their properties, have many potential applications. One of the most promising seems to be nuclear waste immobilization. Radioactive 90Sr isotope is the main short-lived product of fission and, due to its high solubility, it can enter groundwater and pose a threat to the environment. On the other hand, Sr is an important element in hard tissue metabolic processes, and phosphate glasses containing Sr are considered bioactive. This study investigated the effect of SrO addition on a glass structure of nominal 30Fe2O3-70P2O5 chemical composition using classical molecular dynamics simulations. To describe the interaction between Sr-O ion pairs, new interatomic potential parameters of the Buckingham-type were developed and tested for crystalline compounds. The short-range structure of the simulated glasses is presented and is in agreement with previous experimental and theoretical studies. The simulations showed that an increase in SrO content in the glass led to phosphate network depolymerization. Analysis demonstrated that the non-network oxygen did not take part in the phosphate network depolymerization. Furthermore, strontium aggregation in the glass structure was observed to lead to the non-homogeneity of the glass network. It was demonstrated that Sr ions prefer to locate near to Fe(II), which may induce crystallization of strontium phosphates with divalent iron.


Author(s):  
Keivan Esfarjani ◽  
Gang Chen ◽  
Asegun Henry

Based on first-principles density-functional calculations, we have developed and tested a force-field for silicon, which can be used for molecular dynamics simulations and the calculation of its thermal properties. This force field uses the exact Taylor expansion of the total energy about the equilibrium positions up to 4th order. In this sense, it becomes systematically exact for small enough displacements, and can reproduce the thermodynamic properties of Si with high fidelity. Having the harmonic force constants, one can easily calculate the phonon spectrum of this system. The cubic force constants, on the other hand, will allow us to compute phonon lifetimes and scattering rates. Results on equilibrium Green-Kubo molecular dynamics simulations of thermal conductivity as well as an alternative calculation of the latter based on the relaxation-time approximation will be reported. The accuracy and ease of computation of the lattice thermal conductivity using these methods will be compared. This approach paves the way for the construction of accurate bulk interatomic potentials database, from which lattice dynamics and thermal properties can be calculated and used in larger scale simulation methods such as Monte Carlo.


Author(s):  
Andrey I. Kartamyshev ◽  
Alexey Gennadievich Lipnitskii ◽  
Anton Boev ◽  
Ivan Nelasov ◽  
Vyacheslav N. Maksimenko ◽  
...  

2012 ◽  
Vol 1407 ◽  
Author(s):  
Andrew L. J. Pang ◽  
Viacheslav Sorkin ◽  
Yong-Wei Zhang

ABSTRACTWe studied the self-assembly mechanisms of Graphene Nanoribbon (GNR) with unsaturated edges and demonstrated the ability of GNR to self-assemble into novel stable structures. We proposed three mechanisms which dictate the self-assembly evolution of GNR with unsaturated edges. Using the Adaptive Intermolecular Reactive Empirical Bond-Order (AIREBO) potential, we performed molecular dynamics simulations on initially-planar GNRs with unsaturated edges. The simulation results showed that the self-assembly mechanisms and final conformations of the GNRs correlate well with the proposed GNR self-assembly mechanisms. Furthermore, the simulations also showed the ability of a narrow GNR to self-assemble into various nanostructures, such as tapered graphene nano-rings and graphene nanoscrolls with an embedded nanotube.


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