Density-functional-based molecular-dynamics simulations of molten salts

2005 ◽  
Vol 123 (13) ◽  
pp. 134510 ◽  
Author(s):  
Sandrine Hazebroucq ◽  
Gérard S. Picard ◽  
Carlo Adamo ◽  
Thomas Heine ◽  
Sibylle Gemming ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Molten Salts ◽  
Density Functional ◽  
Dynamics Simulations

Graphene adlayer growth between nonepitaxial graphene and Ni(111) substrate: a promising theoretical scheme

2020 ◽  
Author(s):  
Lijuan Meng ◽  
Jinlian Lu ◽  
Yujie Bai ◽  
Lili Liu ◽  
Tang Jingyi ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
Chemical Vapor Deposition ◽  
Molecular Dynamics Simulations ◽  
Vapor Deposition ◽  
Density Functional ◽  
Chemical Vapor ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Dynamics Simulations

Understanding the fundamentals of chemical vapor deposition bilayer graphene growth is crucial for its synthesis. By employing density functional theory calculations and classical molecular dynamics simulations, we have investigated the...

Cluster, Surface and Bulk Properties of ZnCd Binary Alloys: Molecular-Dynamics Simulations

2005 ◽  
Vol 502 ◽  
pp. 51-56 ◽  
Author(s):  
Sakir Erkoc
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Density Functional ◽  
Structural Features ◽  
Bulk Materials ◽  
Bulk Properties ◽  
Atom Clusters ◽  
Dynamics Simulations ◽  
Mixed Clusters ◽  
Stable Structures

The structural and electronic properties of isolated neutral ZnmCdn clusters for m+n £ 3 have been investigated by performing density functional theory calculations at B3LYP level. The optimum geometries, vibrational frequencies, electronic structures, and the possible dissosiation channels of the clusters considered have been obtained. An empirical many-body potential energy function (PEF), which comprices two- and three-body atomic interactions, has been developed to investigate the structural features and energetics of ZnmCdn (m+n=3,4) microclusters. The most stable structures were found to be triangular for the three-atom clusters and tetrahedral for the four-atom clusters. On the other hand, the structural features and energetics of Znn-mCdm (n=7,8) microclusters, and Zn50, Cd50, Zn25Cd25, Zn12Cd38, and Zn38Cd12 nanoparticles have been investigated by performing molecular-dynamics computer simulations using the developed PEF. The most stable structures were found to be compact and three-dimensional for all elemental and mixed clusters. An interesting structural feature of the mixed clusters is that Zn and Cd atoms do not mix in mixed clusters, they come together almost without mixing. Surface and bulk properties of Zn, Cd, and ZnCd systems have been investigated too by performing molecular-dynamics simulations using the developed PEF. Surface reconstruction and multilayer relaxation on clean surfaces, adatom on surface, substitutional atom on surface and bulk materials, and vacancy on surface and bulk materials have been studied extensively.

scholarly journals Molecular Insights into Cage Occupancy of Hydrogen Hydrate: A Computational Study

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 699 ◽  
Author(s):  
Ma ◽  
Zhong ◽  
Liu ◽  
Zhong ◽  
Yan ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Storage ◽  
Molecular Dynamics Simulations ◽  
Density Functional ◽  
Storage Capacity ◽  
Computational Study ◽  
Density Functional Theory Calculations ◽  
Hydrogen Storage Capacity ◽  
Large Cage ◽  
Dynamics Simulations

Density functional theory calculations and molecular dynamics simulations were performed to investigate the hydrogen storage capacity in the sII hydrate. Calculation results show that the optimum hydrogen storage capacity is ~5.6 wt%, with the double occupancy in the small cage and quintuple occupancy in the large cage. Molecular dynamics simulations indicate that these multiple occupied hydrogen hydrates can occur at mild conditions, and their stability will be further enhanced by increasing the pressure or decreasing the temperature. Our work highlights that the hydrate is a promising material for storing hydrogen.

scholarly journals Multiscale QM/MM Molecular Dynamics Simulations of the Trimeric Major Light-Harvesting Complex II

2021 ◽  
Author(s):  
Sayan Maity ◽  
Vangelis Daskalakis ◽  
Marcus Elstner ◽  
Ulrich Kleinekathöfer
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Chlorophyll A ◽  
Density Functional ◽  
Light Harvesting ◽  
Higher Plants ◽  
Tight Binding ◽  
Spectral Densities ◽  
Light Harvesting Complex ◽  
Dynamics Simulations

Photosynthetic processes are driven by sunlight. Too little of it and the photosynthetic machinery cannot produce the reductive power to drive the anabolic pathways. Too much sunlight and the machinery can get damaged. In higher plants, the major Light Harvesting Complex (LHCII) efficiently absorbs the light energy, but can also dissipate it when in excess (quenching). In order to study the dynamics related to the quenching process but also the exciton dynamics in general, one needs to accurately determine the so-called spectral density which describes the coupling between the relevant pigment modes and the environmental degrees of freedom. To this end, Born–Oppenheimer molecular dynamics simulations in a quantum mechanics/molecular mechanics (QM/MM) fashion utilizing the density functional based tight binding (DFTB) method have been performed for the ground state dynamics. Subsequently, the time-dependent extension of the long-range-corrected DFTB scheme has been employed for the excited state calculations of the individual chlorophyll-a molecules in the LHCII complex. The analysis of this data resulted in spectral densities showing an astonishing agreement with the experimental counterpart in this rather large system. This consistency with an experimental observable also supports the accuracy, robustness, and reliability of the present multi-scale scheme. In addition, the resulting spectral densities and site energies were used to determine the exciton transfer rate within a special pigment pair consisting of a chlorophyll-a and a carotenoid molecule which is assumed to play a role in the balance between the light harvesting and quenching modes.

scholarly journals First-Principles-Based Interatomic Potential for SI and Its Thermal Conductivity

2011 ◽  
Author(s):  
Keivan Esfarjani ◽  
Gang Chen ◽  
Asegun Henry
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Thermal Properties ◽  
Force Field ◽  
Molecular Dynamics Simulations ◽  
First Principles ◽  
Density Functional ◽  
Interatomic Potential ◽  
Force Constants ◽  
Dynamics Simulations

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.

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