Modelled a-, b- and c-axis lengths of stishovite to post-stishovite as a function of pressure and temperature. Data points are from the published literature (Ito et al. 1974; Andrault et al. 2003; Nishihara et al. 2005; Wang et al. 2012; Fischer et al. 2018; Zhang et al. 2021). The pressures of the high pressure data are adjusted as described in Section 5.3.