Similarly, the larger tail tilt of MMG-6 possibly serves to maintain an optimal tail packing distance, despite the larger tail splay near the glycerol moiety. Interestingly, tilt angles have been suggested to increase only up to a certain threshold until the bilayer interdigitates, at least in the case of alcohol-induced interdigitation of phospholipids; 52 coarse-grained simulations of Kranenburg et al., did not, however, show an increase in the tilt angle, but this is likely to be due to the relatively large degree of coarse-graining. Therefore, it is possible that MMG-6 interdigitates when the tail tilt alone is not sufficient to maximize the van der Waals interactions. However, the enthalpic penalty of changing from a tilted tail configuration to that observed in the interdigitated state (Figure ) may counteract this.