The F-Si RDFs of SiO2-AST systems are shown in Figure and the average structures computed from individual trajectories are visualised in Figures and. The F-Si RDFs of SiO2-AST_TMA show a symmetric maximum centred at ~2.65 Å, which corresponds to oscillations of fluoride about its equilibrium location at the centre of the cage, replicating the findings from the earlier AIMD study of this system. Due to increased thermal motion, the maximum becomes broader with increasing temperature. The lower part of Figure overlays the trajectories of one individual fluoride anion inside a d4r cage with the time-averaged positions of the surrounding framework atoms. It is apparent that the number of short Si-F contacts (below 2.3 Å) increases with temperature due to the more vigorous motion of the fluoride anion, and that such short contacts occur without any preferential direction of displacement.