ENABLING ACCURATE THERMAL TRANSPORT CALCULATIONS IN LAMMPS

Molecular dynamics (MD) simulations are used extensively to study thermal transport in materials, and one of the most widely used MD software packages is LAMMPS. However, the most common MD technique to compute thermal conductivity, the Green-Kubo method, yields incorrect results in LAMMPS for the majority of molecular simulations. Unless correct thermal transport calculations can be achieved and implemented for this widely used and highly optimized software package, research and development of materials with novel thermal properties will be significantly hindered. It is the primary aim of this NSF CSSI project to create and carefully implement the correct heat flux computation in LAMMPS, a problem made challenging by the fact that this software has hundreds of thousands of users and the solution must be merged into the core LAMMPS code. The objectives of the project are: (1) to implement a corrected heat flux computation for all supported many-body potentials in LAMMPS, (2) to identify the types of molecular systems most affected by the changed heat flux computations, and (3) apply and refine the methodology to predict thermal conductivity for several novel nanomaterials.