For chabazite, NTE is found for the whole T range explored and show the largest (negative) thermal expansion coefficient αV among the investigated frameworks -13.07 10 -6 K -1 between 300 and 900 K, in qualitative agreement with the experimental value (-28.5 10 -6 K -1 ). At difference with the experiments, simulations found a larger expansion rate at low temperature. Moreover, CHA, being a non-cubic framework, has an anisotropic expansion.