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N - Towards Experimentally Relevant Time Scales: Methods for Extending Atomistic Simulation Times and Their Applications in Material Science

Organizers

Chadwick Sinclair
(Univ. of British Columbia, Canada)
Danny Perez
(Los Alamos National Laboratory, USA)
Jutta Rogal
(Ruhr-Universität Bochum, Germany)
Normand Mousseau
(Univ. Montreal, Canada)
Erik Bitzek
(Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany)
Shotaro Hara
(Chiba Institute of Technology, Japan)

Description

Direct atomistic simulations have tremendously advanced our understanding of the thermo-mechanical and functional properties of materials. However, such simulations are generally limited to short time scales, often much shorter than required for relevant unit processes to operate; this is the so-called “rare event” problem. Extending the time scales amenable to direct atomistic simulations is an enduring challenge in computational materials sciences.

In order to overcome these limitations, specialized simulation techniques are required which allow for evolving atomistic configurations on experimentally relevant time scales. For example, the reach of direct molecular dynamics can be extended using accelerated MD techniques (e.g., parallel replica dynamics, hyperdynamics). Alternatively, one can avoid the problem of being slaved to phonon frequencies by using techniques that seek to sample the energy landscape and advance the system based on transition state theory, e.g., adaptive kinetic Monte Carlo. Finally, rather than starting from the atomistic scale and coarse graining (in time) to achieve the required time scales, techniques like Diffusive Molecular Dynamics or Phase Field Crystal have been developed that start from concepts closely linked to continuum classic density functional theory, mapping this approach into an atomistic landscape.

The aim of this symposium is to bring together researchers working on the development and application of time accelerated, atomistically resolved, simulation techniques and to illustrate how they can be used to address a wide variety of problems in the condensed state.

Topics of interest would include:

  • Development of novel time scale extension techniques
  • Simulation of processes occurring over vastly different time scales
  • Inclusion of long time scale methods in concurrent multiscale modeling frameworks
  • Massively-parallel long time scale methods
  • Applications in materials science, including, but not limited to: atomic diffusion in topologically complex materials and in heterogeneous strain fields, evolution of phase and grain boundaries, prediction of segregation and properties affected by segregation, modeling of plasticity and creep in crystalline and non-crystalline materials.

Invited speakers

  • "Multiscale diffusion method for simulations of long-time defect evolution with application to dislocation climb"
  • By Kristopher Baker, Knolls Atomic Power Laboratory, USA
  • "Dynamics of C atoms nearby extended defects: a multi technique approach"
  • By Charlotte Becquart, Univ. Lille, France
  • "Modelling metals, alloys and cement paste across length and time scales"
  • By Laurent Karim Béland, MIT USA/ Queen’s Univ., Canada
  • "Temperature Programmed Molecular Dynamics - Accessing rare events using a combination of finite time sampling and bias potentials"
  • By Abhijit Chatterjee, IIT Bombay, India
  • "Kinetics of Fivefold-Twinned Nanowire Growth"
  • By Kristen Fichthorn, Univ. Penn, USA
  • "From transition states to dynamics over long time scales"
  • By Graeme Henkelman, UT Austin, USA
  • "Shape fluctuation of metallic nanoclusters: observations from long-timescale simulations"
  • By Rao Huang, Xiamen University, China
  • "Accelerated dynamics: mathematical foundations and generalizations"
  • By Tony Lelievre, ENPC, France
  • "Atomistic Simulations that Reach Anthropological Timescale and Beyond"
  • By Ju Li, MIT, USA
  • "Modeling Microstructure Evolution in Rapid Solidification Phenomena Using Structural Phase Field Crystal Models"
  • By Nikolas Provatas, McGill, Canada
  • "Accelerated Sampling with Local Entropy"
  • By Gideon Simpson, Drexel University, USA
  • "Bridging Time Scales with Variationally Enhanced Sampling"
  • By Omar Valsson, Max Planck Institute for Polymer Research, Germany
  • "Increasing the power of accelerated molecular dynamics methods and plans to exploit the coming exascale"
  • By Art Voter, LANL, USA