The system was finally equilibrated for 100 ps, during which the calculation of the glass properties is performed. The four steps of this procedure are represented on Figure . The entire procedure was performed in the (N, V, T ) ensemble. To reduce finite size effects, a (2 × 2 × 2) supercell of ZIF-4 with 2 176 atoms was simulated, with periodic boundary conditions. We checked that the use of a supercell led to a slight change in the properties of the generated glasses, compared to only simulating one unit cell (see details on Figure ). Melt-quenching is mainly parameterized by the maximal temperature T max and the heating/cooling rate r. Consistently with the previous ab initio work, we aimed for a maximal temperature of 1500 K, and chose a rate of 20 K/ps. Contrary to ReaxFF simulations which led to excessive decoordination, we find that ZIF-4 in simulations with the MLP does not melt that easily. After a procedure consisting of only two ramps (one for heating, one for cooling), as with ReaxFF, the final system was still crystalline for T max = 1500 K and r in the 50-2.5 K/ps region. Either lowering the rate to r = 1 K/ps, or increasing the temperature to T max = 1900 K, both led to the successful formation of glasses. However, the first option requires rather long simulations, while the second leads to an increased risk of loss of physical integrity.