Silica is a common material with a wide range of commercial applications – including the production of glass, concrete and semiconductors. This makes accurately modelling its properties using molecular dynamics particularly important. Furthermore, procedures for calculating the physical properties of silica can be often generalized for other oxide materials [1].
Recently, a new interbody potential for modelling silicon dioxide interactions has been developed. It has been shown that this potential allows for accurate prediction of the physical properties of amorphous silica even under high pressures with decreased intermolecular distance [1]. Our recent research has shown, that the value of the heat conductivity coefficient can vary substantially depending on the method used. This study attempts to develop an accurate method for calculating heat conductivity of silica using the equilibrium Green-Kubo [2] method and non-equilibrium Müller-Plathe method [3].
Obtaining accurate results turned out to be non-trivial, particularly using the Green-Kubo method. Molecular dynamics simulations in the LAMMPS [4] environment have been conducted in order to compare the results across the two methods and different procedures for obtaining the final heat conductivity value. The aim is to evaluate the results obtained from those methods by comparing them with each other and the known experimental values. The relationship between the heat conductivity coefficient and pressure can also be determined and can serve as an another way to evaluate the results.