Tools and Techniques for Development of High-fidelity Interatomic Potentials

National Laboratory: 
Sandia National Laboratories
Characterization Class: 
Mechanical Behavior of Materials
Computational Tools Class: 
Process-Structure
Description: 

Sandia National Laboratories’ Mechanics of Materials Department has tools and techniques specialized for the development of high-fidelity interatomic potentials, used in molecular dynamics simulations and multiscale modeling. These methods are used to develop interaction models between hydrogen and lightweight materials, such as aluminum, for understanding mechanical properties under application environments. SNL’s capability affords the ability to study materials posed for examination rather than materials that have interatomic potentials available in the literature. This ability also allows the fidelity of the molecular dynamics models to excel beyond previous ones because we can iteratively modify the potentials based on the predicted results for the particular problem being studied. This capability can produce predictive estimates of mechanical and thermal properties of new materials, e.g., fracture strength, dislocation energies, or thermal conductivities.

Capability Bounds: 

Direct molecular dynamics simulations are bounded in both time and length scales, but fundamental laws derived from simulations can be applicable for large time and length scales. These scales can be estimated via molecular techniques developed at SNL, and, in most cases, large-scale/bulk estimates can be made.

Unique Aspects: 

Interatomic potentials developed at SNL have unique abilities, such as being capable of simulating chemical reactions and vapor deposition processes, along with capturing property trends of a range of metastable phases. SNL also has techniques for extracting continuum fields and properties directly from simulations with atomic detail, e.g., fracture in thermal and/or reacting environments.

Availability: 

New potential implementation and parameter files have been released with the LAMMPS package and are available to a broad research community, as are the field and property estimation tools.

Single Point of Contact: 

Name: Xiaowang Zhou
Email: xzhou@sandia.gov
Phone: 925-294-2851

References: 
  1. X. W. Zhou, D. K. Ward, and M. E. Foster, An analytical bond-order potential for carbon, J. Comp. Chem., 36, 1719-1735, 2015; X. W. Zhou, D. K. Ward, M. Foster, and J. A. Zimmerman, An analytical bond-order potential for the copper-hydrogen binary system, J. Mater. Sci., 50, 2859,-2875, 2015; J. A. Zimmerman, and R. E. Jones. The application of an atomistic J-integral to a ductile crack. J. Phys.-Cond.Mat., 25(15):155402, 2013
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