A minimal Tersoff potential for diamond silicon with improved descriptions of elastic and phonon transport properties

Research output: Contribution to journalArticleScientificpeer-review

Researchers

Research units

  • Bohai University
  • University of Science and Technology Beijing
  • Shanghai Jiao Tong University
  • Loughborough University

Abstract

Silicon is an important material and many empirical interatomic potentials have been developed for atomistic simulations of it. Among them, the Tersoff potential and its variants are the most popular ones. However, all the existing Tersoff-like potentials fail to reproduce the experimentally measured thermal conductivity of diamond silicon. Here we propose a modified Tersoff potential and develop an efficient open source code called GPUGA (graphics processing units genetic algorithm) based on the genetic algorithm and use it to fit the potential parameters against energy, virial and force data from quantum density functional theory calculations. This potential, which is implemented in the efficient open source GPUMD (graphics processing units molecular dynamics) code, gives significantly improved descriptions of the thermal conductivity and phonon dispersion of diamond silicon as compared to previous Tersoff potentials and at the same time well reproduces the elastic constants. Furthermore, we find that quantum effects on the thermal conductivity of diamond silicon at room temperature are non-negligible but small: Using classical statistics underestimates the thermal conductivity by about 10% as compared to using quantum statistics.

Details

Original languageEnglish
Article number135901
Number of pages9
JournalJournal of Physics Condensed Matter
Volume32
Issue number13
Publication statusPublished - 1 Jan 2020
MoE publication typeA1 Journal article-refereed

    Research areas

  • Empirical potential fitting, Genetic algorithm, Graphics processing units, Molecular dynamics (md) simulation, Phonon dispersion, Tersoff potential, Thermal conductivity

ID: 41323155