To estimate the uncertainty due to the fluctuations and limited simulation time, the last 50 ps were divided into blocks of 5 ps. The average pressure of each block was computed, and a standard deviation was calculated on these 10 values. Both the bulk modulus K and the extrapolated density at zero pressure ρ 0 were obtained by fitting the P -V data with the second order Birch-Murnaghan EoS. Results are shown on Table . The P -V plot with the standard deviations as well as the fitted EoS is shown on Figure in the case of the crystal. We note that despite the large pressure fluctuations of Figure , inherent to the computation of stresses in molecular dynamics simulations, we obtain a reasonable averaged pressure for each volume. The same procedure was then used for the glass models, although the complex energy landscapes of ZIF systems -prone to polyamorphism under the application of temperature or pressure -meant that it was not straightforward to observe a well-behaved P (V ) regime for a large range of volumes. As illustrated on Figure Table : Bulk moduli K and densities at zero pressure ρ 0 for the ZIF-4 crystal and glasses obtained by AIMD with the finite strain difference method. Glass values are averaged over 3 models.