Transferability of interatomic potentials with insights into the structure-property relationship of SiO2-CaO-MgO-Al2O3 melts

Molecular dynamics (MD) simulations were carried out to validate the transferability of Matsui, Kawamura, Miyake, and Guillot potentials on the composition-structure-property relationship of liquid SiO2-CaO-MgO-Al2O3 (CMAS) melts in a wide range of chemical compositions at 1773K. Results revealed that Matsui, Miyake, and Guillot potentials were able to reproduce experimentally observed local atomic structures and properties while Kawamura potential cannot. Even though an accurate trend can be obtained, the values of properties obtained with Miyake, Matsui and Guillot potentials varied obviously with each other. Viscosity obtained using Einstein-Stokes method is about one magnitude lower than experimental viscosity, while viscosities obtained with Green-Kubo and reverse nonequilibrium molecular dynamics methods underestimate the viscosity by about two magnitudes. The increase in CaO/SiO2 ratio under fixed MgO/Al2O3 ratio and the increase in MgO/Al2O3 ratio under fixed CaO/SiO2 ratio can both decrease the polymerisation degree of system, which finally decreases the viscosity. The influence of adding a Morse term to BMH potential is very slightly. This paper provides the foundation to further simulate the atomic structure of CMAS system and further optimise the Born-Mayer-Higgins potential for various oxide systems.