We will discuss a force matching method that has been demonstrated to be very effective for force field optimization to describe the lattice thermal conductivity of Si-based nanostructures.  The force-matching approach can also be broadly applicable to other materials system.  Using this method we have optimized the parameters of the Stillinger-Weber interatomic potential based on first-principles density-functional calculations of the restoring forces for atomic displacements. The thermal conductivities of Si-based nanostructures estimated using nonequilibrium MD with modified parameter sets show excellent agreement with existing experimental data.  This presentation will also touch on how the force matching-based parameterization can provide improved estimation of thermal conductivity, as compared to the original SW parameter set, through analysis of phonon density of states.  This work provides an important hint on how to obtain more reliable force fields for description of the lattice thermal conductivity of various materials, essential for development of effective thermoelectric devices.

Force matching-based force field optimization for thermal conductivity prediction

245th National Meeting (2013)

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