An improved interatomic potential function for thermoelectric Mg2Si: A combination study of ab-initio and molecular dynamics method

The appropriate interatomic potential function is of vital importance for the prediction of a material's various properties in theoretical modeling and simulations such as molecular dynamics. Here we develop an improved interatomic potential for use in thermoelectric (TE) Mg2Si, which is fit to density functional theory and is further verified by the molecular dynamics simulation. We find that this interatomic potential can well predict the structural, elastic, and thermodynamics properties of Mg2Si such as elastic constants, thermal expansion, heat capacity, and thermal conductivity, while these predicted results show good agreement with the experimental reports. This work is beneficial for the development of powerful theoretical modeling and simulations to accurately predict various properties of Mg2Si, which can be also applied in other TE or non-TE energy materials.