Molecular Dynamics Simulation of Aerogel Silica on Parallel Computers

1992 ◽  
Vol 293 ◽  
Author(s):  
Aiichiro Nakano ◽  
Rajiv K. Kalia ◽  
Priya Vashishta
Keyword(s):  
Molecular Dynamics ◽  
Neutron Scattering ◽  
Particle System ◽  
Dynamics Simulation ◽  
Scattering Data ◽  
Communication Overhead ◽  
Multiple Time ◽  
Time Step ◽  
Three Body ◽  
Force Calculation

AbstractMolecular dynamics (MD) simulations of porous silica, in the density range 2.2 - 0.1 g/cm3, are carried out on a 41,472 particle system using two- and three-body interatomic potentials. Calculated results for fractal dimension and small-angle neutron scattering data are in good agreement with neutron scattering experiments. Results for structural correlations reveal crossovers from the short- to intermediate range (< 8 Å) and fractal to large-scale regime (10 ∼ 100 Å).The MD program simulations are carried out on distributed-memory MIMD computers using a domain-decomposition algorithm. The algorithm employs the linked-celllist method and separable three-body force calculation. The force calculation is accelerated by the multiple-time-step method. The parallel algorithm is highly efficient (parallel efficiency = 0.974), as it involves only 3 % communication overhead.

Parallel multiple-time-step molecular dynamics with three-body interaction

1993 ◽  
Vol 77 (3) ◽  
pp. 303-312 ◽  
Author(s):  
Aiichiro Nakano ◽  
Priya Vashishta ◽  
Rajiv K. Kalia
Keyword(s):  
Molecular Dynamics ◽  
Multiple Time ◽  
Time Step ◽  
Body Interaction ◽  
Multiple Time Step ◽  
Three Body

Molecular dynamics simulation of atactic polystyrene. 2. Comparison with neutron scattering data

1994 ◽  
Vol 27 (20) ◽  
pp. 5674-5680 ◽  
Author(s):  
Hidemine Furuya ◽  
M. Mondello ◽  
Hyung-Jin Yang ◽  
Ryong-Joon Roe ◽  
R. W. Erwin ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Neutron Scattering ◽  
Dynamics Simulation ◽  
Scattering Data ◽  
Atactic Polystyrene

Molecular Dynamics and X-Ray Diffraction Study of Aqueous Beryllium(II) Chloride Solutions

1986 ◽  
Vol 41 (10) ◽  
pp. 1175-1185 ◽  
Author(s):  
T. Yamaguchi ◽  
H. Ohtaki ◽  
E. Spohr ◽  
G. Pálinkás ◽  
K. Heinzinger ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Md Simulation ◽  
Hydration Shell ◽  
Dynamics Simulation ◽  
Scattering Data ◽  
Water Molecules ◽  
Force Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
Three Body

A structural investigation of a 1.1 molal BeCl2 aqueous solution has been performed by a molecular dynamics simulation together with X-ray diffraction studies of 1.1 and 5.3 molal BeCl2 aqueous solutions at pH =1. A central force model in combination with an improved intramolecular three-body potential was used for water. The ion-water and ion-ion potentials were derived from ab initio calculations. The structure function obtained from the simulation is in satisfactory agreement with that from X-ray diffraction. The MD simulation of the 1.1 molal solution shows that the hydration shell o f Be2+ consists of six water molecules occupying octahedral sites around a central Be2+. The X-ray scattering data of the 5.3 molal solution indicate that Be2+ has only four water molecules in the first hydration shell. The average coordination number of Cl- is found to be about seven in the 1.1 molal solution from both X-ray diffraction and MD simulation, but Cl- is surrounded on the average by 3.4 water molecules in the 5.3 molal solution. The influence of the small divalent Be2+ on the geometry of its nearest neighbour water molecules is compared with the results of previous simulations of 1.1 molal MgCl2 and CaCl2 solutions.

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