Fig. 2: Elastic properties.
From: A machine-learned interatomic potential for silica and its relation to empirical models
a Energy--volume curves of different silica polymorphs. Solid black lines correspond to calculations using the GAP model for silica developed in the present work. The GAP agrees well with the SCAN-DFT data (coloured symbols). For the low-temperature tridymite structure, however, the GAP predicts that it becomes unstable at certain strains and data are therefore only shown in the stability region. b Root mean square error (RMSE) and mean absolute percentage error (MAPE) of elastic constants as predicted by various potentials against experimental data for α-quartz105, α-cristobalite6, coesite106, and stishovite107. The Vashishta and Broughton potentials do not predict a stable stishovite structure (“---”). Note that large deviations from a small reference value can lead to errrors exceeding 100%. Colour coding from yellow to red emphasises the magnitude of the respective error.
