The packing of the new cholesterol model in the crystal structures of pure cholesterol (CCDC code: CHOEST20) and cholesterol monohydrate (CCDC code: CHOLES20) was also tested. Supplementary Figure shows the CG crystal structures as well as the averaged structures of 200 ns of CG simulation at 200 K. The increase in disorder is more pronounced for the cholesterol monohydrate than for pure cholesterol. An increase in disorder compared to the atomistic structures is to be expected due to the smoothened molecular surface (Fig. ). The higher disorder in the monohydrate could be explained by the smoothened spherical surface of the tiny TW bead and a slight size mismatch compared to a water molecule. The introduced harmonic bonds to mimic the hydrogen bonds cannot fully compensate for the loss of molecular symmetry. Table shows the changes of the unit cells for the CG structure of CHOEST20 compared to experiment. The simulated unit cells deviate by 0-7% of the box vector length. While the box vectors a and b are slightly smaller or larger than the experimental ones, c is smaller by 7% at 200 K and 6% at 295 K, respectively. The absolute changes are also most pronounced for c. Overall, the unit cell volume decreases by 5-6%. For cholesterol monohydrate, the changes of the three box vectors are comparable to the ones of the pure cholesterol structure (Table ). While a shrinking by 2% and 11% at 200 K and 295 K, respectively, b and c increase by 1-6% except for b at 200 K which slightly decreases. The unit cell volume shrinks by 2% at 200 K and by less than 1% at 295 K, respectively. In summary, the crystal structure simulations confirm the well reproduced shape and packing of the new Martini 3 cholesterol model.