Unfortunately, the only experimental results reported on the thermal expansion of LTA are limited to the low temperature regime, between 100-300 K, where a strong NTE was observed, with a mean thermal expansion coefficient (300 to 100 K) of -22.1 10 -6 K -1 . At this stage, it is unclear whether the origin of this discrepancy at low temperature comes from an inadequacy of the MLIP (which was trained mostly on high-temperature data) or from the DFT calculations themselves.