P-TRANS: A Monte Carlo ray-tracing software to simulate phonon transport in arbitrary nanostructures

Abstract

P-TRANS is a software to simulate phonon transport in arbitrary nanostructures based on the Boltzmann transport theory. The core part of the software is a Monte Carlo ray-tracing solver that uses the stochastic method to sample phonon transport in various nanostructures. The solver is written in FORTRAN with well-organized modules and utilizing the OpenMP and MPI parallelization to achieve high performance. The software can handle a typical calculation of nanostructures with a feature size of ∼1000 nm on a normal PC within seconds, which is useful when exploring the wide variety of structures, for instance for structural optimization or high-throughput screening in material informatics. The software takes the bulk phonon properties obtained from the first-principles anharmonic lattice dynamics calculations as inputs. The database of bulk phonon properties is available on the software webpage, which currently contains more than 60 materials and will increase in the future. We also provide a graphical user interface to design the nanostructures and to run the simulation for non-expert users. In this paper, we introduce the theoretical background, the technical details and implementation, and the applications of the software. Program summaryProgram title:P-TRANSCPC Library link to program files:https://doi.org/10.17632/n76jpj3fnz.1Developer's repository link:https://github.com/TEEL-UTokyo/P-TRANSCode Ocean capsule:https://codeocean.com/capsule/9387119Licensing provisions: GPLv3Programming language: FortranSupplementary material:http://www.phonon.t.u-tokyo.ac.jp/p-trans/Nature of problem: Knowing the effective thermal conductivity of nanostructures is important for numerous applications. Phonons are the dominate heat carriers in dielectrics and their transport is influenced by the voids, grain boundaries, and free surfaces in the nanostructure. Here we are focusing on the effective thermal conductivities of nanostructures with complex geometries and boundaries.Solution method: Monte Carlo ray tracing simulations.