The initial structures for DFT-MD calculations were equilibrated through simulations with CMD-Du before running DFT-MD. This procedure was used to obtain the equilibrium state for starting DFT-MD. The simulation steps are shown in Fig. and represent a commonly used route for simulation of oxide glasses. The system was first melted for 100 ps at 6000 K and then equilibrated for 100 ps at 5000 K to obtain stable glass melts. It was subsequently cooled at a rate of 5 K/ps to obtain solid glass structures. An equilibration run of the solid glass was then conducted for 100 ps. The structure at the last step was further relaxed by the conjugated gradient method to satisfy a force of 1 × 10 -4 kcal/ Å/mol. All ensembles were canonical ensembles (NVT) with a time step of 1 fs. The Nosé-Hoover thermostat was used for control of temperature, and the LAMMPS code was used for CMD-Du.