Nonlinear Molecular Dynamics and Monte Carlo Simulations of Crystals at Constant Temperature and Tensorial Pressure

1992 ◽  
Vol 291 ◽  
Author(s):  
J.V. Lill
Keyword(s):  
Molecular Dynamics ◽  
Monte Carlo ◽  
Constant Temperature ◽  
Interatomic Potential ◽  
External Pressure ◽  
Elastic Response ◽  
The Novel ◽  
Monte Carlo Algorithms ◽  
Metropolis Monte Carlo ◽  
Nonlinear Elastic

ABSTRACTComplimentary molecular dynamics and Metropolis Monte Carlo algorithms for the atomistic simulation of crystals at constant temperature and homogeneous tensorial pressure are summarized. The novel aspect of computational physics which unites these methods is the extension of the virial theorem to nonlinear elastic media. This guarantees the dynamical balance between the internal pressure, as determined by the interatomic potential, and effective external pressure, as determined by the applied laboratory pressure, and includes the elastic response of the material. Numerical examples are presented.

Erratum: Nonlinear molecular dynamics and Monte Carlo algorithms

1993 ◽  
Vol 48 (5) ◽  
pp. 3580-3580
Author(s):  
J. V. Lill ◽  
Jeremy Q. Broughton
Keyword(s):  
Molecular Dynamics ◽  
Monte Carlo ◽  
Monte Carlo Algorithms

A method for analyzing nanomechanical deformation of nanocrystalline Ni at higher timesteps than is possible in classical molecular dynamics

2006 ◽  
Vol 978 ◽  
Author(s):  
Vikas Tomar
Keyword(s):  
Molecular Dynamics ◽  
Monte Carlo ◽  
Strain Rate ◽  
Defect Formation ◽  
Interatomic Potential ◽  
Md Simulations ◽  
Classical Molecular Dynamics ◽  
Rate Dependent ◽  
Nanocrystalline Structures ◽  
Defect Nucleation

AbstractA majority of computational mechanical analyses of nanocrystalline materials have been carried out using classical molecular dynamics (MD). Due to the fundamental reason that the MD simulations must resolve atomic level vibrations, they cannot be carried out at the timescale of the order of microseconds. Additionally, MD simulations have to be carried out at very high loading rates (∼108 s−1) rarely observed in experiments. In this investigation a modified Hybrid Monte Carlo (HMC) method that can be used to analyze time-dependent (strain rate dependent) atomistic mechanical deformation of nanocrystalline structures at higher timescales than currently possible using MD is established. In this method there is no restriction on the size of MD timestep except that it must be such that to ensure a reasonable acceptance rate between consecutive Monte-Carlo (MC) time-steps. For the purpose of comparison HMC analyses of a nanocrystalline Ni sample at a strain rate of 109 s−1 with three different timesteps, viz. 2 fs, 4fs, and 8 fs, are compared with the analyses based on MD simulations at the same strain rate and a MD timestep of 2 fs. MD simulations of nanocrystalline Ni reproduce the defect nucleation and propagation results as well as strength values reported in the literature. In addition, HMC with timestep of 8 fs correctly reproduces defect formation and stress-strain response observed in the case of MD simulations with permissible timestep of 2 fs (for the interatomic potential used 2 fs is the highest MD timestep). Simulation time analyses show that by using HMC a saving of the order of 4 can be achieved bringing the atomistic analyses closer to the continuum timescales.

Nonlinear molecular dynamics and Monte Carlo algorithms

1992 ◽  
Vol 46 (18) ◽  
pp. 12068-12071 ◽  
Author(s):  
J. V. Lill ◽  
Jeremy Q. Broughton
Keyword(s):  
Molecular Dynamics ◽  
Monte Carlo ◽  
Monte Carlo Algorithms
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