A large-scale and long-time molecular dynamics study of supercritical Lennard-Jones fluid. An analysis of high temperature clusters

1997 ◽  
Vol 107 (6) ◽  
pp. 2020-2033 ◽  
Author(s):  
Noriyuki Yoshii ◽  
Susumu Okazaki
Keyword(s):  
Molecular Dynamics ◽  
High Temperature ◽  
Large Scale ◽  
Lennard Jones ◽  
Long Time

scholarly journals Entire crystallization process of Lennard-Jones liquids: A large-scale molecular dynamics study

2020 ◽  
Vol 152 (5) ◽  
pp. 054903 ◽  
Author(s):  
Wenze Ouyang ◽  
Bin Sun ◽  
Zhiwei Sun ◽  
Shenghua Xu
Keyword(s):  
Molecular Dynamics ◽  
Large Scale ◽  
Crystallization Process ◽  
Lennard Jones

High-Temperature Decomposition of Diisopropyl Methylphosphonate (DIMP) on Alumina: Mechanistic Predictions from Ab Initio Molecular Dynamics

2021 ◽  
Author(s):  
Sohag Biswas ◽  
Bryan Wong
Keyword(s):  
Molecular Dynamics ◽  
High Temperature ◽  
Metal Oxide ◽  
Large Scale ◽  
Activation Barrier ◽  
Chemical Warfare Agents ◽  
Ab Initio Molecular Dynamics ◽  
Oxide Surfaces ◽  
Metal Oxide Surfaces ◽  
Warfare Agents

The enhanced degradation of organophosphorous-based chemical warfare agents (CWAs) on metal-oxide surfaces holds immense promise for neutralization efforts; however, the underlying mechanisms in this process remain poorly understood. We utilize large-scale quantum calculations for the first time to probe the high-temperature degradation of diisopropyl methylphosphonate (DIMP), a nerve agent simulant. Our Born-Oppenheimer molecular dynamics (BOMD) calculations show that the gamma-Al2O3 surface shows immense promise for quickly adsorbing and destroying CWAs. We find that the alumina surface quickly adsorbs DIMP at all temperatures, and subsequent decomposition of DIMP proceeds via a propene elimination. Our BOMD calculations are complemented with metadynamics simulations to produce free energy paths, which show that the activation barrier decreases with temperature and DIMP readily decomposes on gamma-Al2O3. Our first-principle BOMD and metadynamics simulations provide crucial diagnostics for sarin decomposition models and mechanistic information for examining CWA decomposition reactions on other candidate metal oxide surfaces.

Large-Scale Molecular Dynamics Simulations of Interstitial Defect Diffusion in Silicon

2002 ◽  
Vol 731 ◽  
Author(s):  
David A. Richie ◽  
Jeongnim Kim ◽  
Richard Hennig ◽  
Kaden Hazzard ◽  
Steve Barr ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Large Scale ◽  
Materials Science ◽  
Tight Binding ◽  
Md Simulations ◽  
Binding Potential ◽  
Interstitial Defect ◽  
Long Time ◽  
Computational Materials ◽  
Dynamics Simulations

AbstractThe simulation of defect dynamics and evolution is a technologicaly relevant challenge for computational materials science. The diffusion of small defects in silicon unfolds as a sequence of structural transitions. The relative infrequency of transition events requires simulation over extremely long time scales. We simulate the diffusion of small interstitial clusters (I1, I2, I3) for a range of temperatures using large-scale molecular dynamics (MD) simulations with a realistic tight-binding potential. A total of 0.25 μ sec of simulation time is accumulated for the study. A novel real-time multiresolution analysis (RTMRA) technique extracts stable structures directly from the dynamics without structural relaxation. The discovered structures are relaxed to confirm their stability.

scholarly journals Molecular Dynamics Simulation of Tolman Length and Interfacial Tension of Symmetric Binary Lennard–Jones Liquid

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1376
Author(s):  
Hideki Kanda ◽  
Wahyudiono ◽  
Motonobu Goto
Keyword(s):  
Molecular Dynamics ◽  
Interfacial Tension ◽  
Large Scale ◽  
Interfacial Area ◽  
Dynamics Simulation ◽  
Continuum Approximation ◽  
Lennard Jones ◽  
Partially Miscible ◽  
Tolman Length ◽  
Dividing Surface

The Tolman length and interfacial tension of partially miscible symmetric binary Lennard–Jones (LJ) fluids (A, B) was revealed by performing a large-scale molecular dynamics (MD) simulation with a sufficient interfacial area and cutting distance. A unique phenomenon was observed in symmetric binary LJ fluids, where two surfaces of tension existed on both sides of an equimolar dividing surface. The range of interaction εAB between the different liquids and the temperature in which the two LJ fluids partially mixed was clarified, and the Tolman length exceeded 3 σ when εAB was strong at higher temperatures. The results show that as the temperature or εAB increases, the Tolman length increases and the interfacial tension decreases. This very long Tolman length indicates that one should be very careful when applying the concept of the liquid–liquid interface in the usual continuum approximation to nanoscale droplets and capillary phase separation in nanopores.

scholarly journals TRILLION-ATOM MOLECULAR DYNAMICS BECOMES A REALITY

2008 ◽  
Vol 19 (09) ◽  
pp. 1315-1319 ◽  
Author(s):  
TIMOTHY C. GERMANN ◽  
KAI KADAU
Keyword(s):  
Molecular Dynamics ◽  
Large Scale ◽  
Shear Instability ◽  
Dynamics Simulation ◽  
Massively Parallel ◽  
Lennard Jones ◽  
Simple Cubic ◽  
Simple Cubic Lattice ◽  
Future Potential ◽  
Large Scale Simulations

By utilizing the molecular dynamics code SPaSM on Livermore's BlueGene/L architecture, consisting of 212 992 IBM PowerPC440 700 MHz processors, a molecular dynamics simulation was run with one trillion atoms. To demonstrate the practicality and future potential of such ultra large-scale simulations, the onset of the mechanical shear instability occurring in a system of Lennard-Jones particles arranged in a simple cubic lattice was simulated. The evolution of the instability was analyzed on-the-fly using the in-house developed massively parallel graphical object-rendering code MD_render.

Pressure Cooker with Composite Bottom Thermo-Mechanical Coupling Simulation

2013 ◽  
Vol 712-715 ◽  
pp. 1058-1061 ◽  
Author(s):  
Xiang Hong Zhang ◽  
Han Yang ◽  
Hao Zhang ◽  
He Liu ◽  
Hong Fen Guo
Keyword(s):  
High Temperature ◽  
Large Scale ◽  
High Efficiency ◽  
Coupling Effect ◽  
Operating Pressure ◽  
Breakdown Pressure ◽  
Mechanical Coupling ◽  
Simulating Calculation ◽  
Long Time ◽  
Type Pressure

t is required to use specialized large-scale pressure cooker to process and cook rice in high altitude. The design of large-scale pressure cooker with composite bottom is a very complicated process, involving in nominal operating pressure, safe pressure and breakdown pressure, etc., especially the advantage of composite-bottom pressure cooker possesses, which are fast heat conduction, high efficiency and energy conservation, but it is very easy to ignore thermo-mechanical coupling effect which the compound aluminum steel of pressure cooker with composite bottom exerted in the hot operation working condition in the process of designing pressure cooker, once the bottom is dropped due to the condition of high temperature, the whole feeding equipment will not work properly. Analysis software ANSYS is applied to make simulating calculation for thermo-mechanical coupling of super-huge type pressure cooker with composite bottom, verifying if it can operate properly in the field condition of long time and high temperature.

Analysis of a one-billion atom simulation of work-hardening in ductile materials

2004 ◽  
Vol 821 ◽  
Author(s):  
Markus J. Buehler ◽  
Alexander Hartmaier ◽  
Mark Duchaineau ◽  
Farid F. Abraham ◽  
Huajian Gao
Keyword(s):  
Molecular Dynamics ◽  
Work Hardening ◽  
Large Scale ◽  
Pair Potential ◽  
Model Material ◽  
Dynamics Simulation ◽  
Ductile Materials ◽  
Lennard Jones ◽  
Cutting Processes ◽  
First Time

AbstractWe analyze a large-scale molecular dynamics simulation of work hardening in a ductile model material comprising of 500 million atoms interacting with a Lennard-Jones pair potential within a classical molecular dynamics scheme. With tensile loading, we observe emission of thousands of dislocations from two sharp cracks. The dislocations interact in a complex way, revealing three fundamental mechanisms of work-hardening. These are (1) dislocation cutting processes, jog formation and generation of point defects; (2) activation of secondary slip systems by cross-slip; and (3) formation of sessile Lomer-Cottrell locks. The dislocations self-organize into a complex sessile defect topology. Our analysis illustrates mechanisms formerly only known from textbooks and observed indirectly in experiment. It is the first time that such a rich set of fundamental phenomena has been seen in a single computer simulation.

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