Aspherical particle models for molecular dynamics simulation

Journal Article · Wed May 22 00:00:00 EDT 2019 · Computer Physics Communications

DOI:https://doi.org/10.1016/j.cpc.2019.05.010· OSTI ID:1529136

Nguyen, Trung Dac ^[1]; Plimpton, Steven J. ^[2]

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1. Vietnam Academy of Science and Technology, Ba Dinh, Hanoi (Vietnam)
2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

In traditional molecular dynamics (MD) simulations, atoms and coarse-grained particles are modeled as point masses interacting via isotropic potentials. For studies where particle shape plays a vital role, more complex models are required. Here, we describe a spectrum of approaches for modeling aspherical particles, all of which are now available (some recently) as options within the LAMMPS MD package. Broadly these include two classes of models. In the first, individual particles are aspherical, either via a pairwise anisotropic potential which implicitly assigns a simple geometric shape to each particle, or in a more general way where particles store internal state which can explicitly define a complex geometric shape. In the second class of models, individual particles are simple points or spheres, but rigid body constraints are used to create composite aspherical particles in a variety of complex shapes. This work discusses parallel algorithms and associated data structures for both kinds of models, which enable dynamics simulations of aspherical particle systems across a wide range of length and time scales. We also highlight parallel performance and scalability and give a few illustrative examples of aspherical models in different contexts.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE; USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC)
• Grant/Contract Number: AC04-94AL85000; AC05-00OR22725; NA0003525
• OSTI ID: 1529136
• Alternate ID(s): OSTI ID: 1775689
• Report Number(s): SAND--2019-0615J; 671692
• Journal Information: Computer Physics Communications, Journal Name: Computer Physics Communications Journal Issue: C Vol. 243; ISSN 0010-4655
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
Aspherical models
Discrete element models
LAMMPS
Molecular dynamics
Parallel algorithms
Rigid body dynamics