Fc12-Br and Fc12-PF6 have opposite effects on the lattice parameter of the MO cubic phase, with the former inducing swelling whereas the latter leads to shrinkage. This might be due to the varying nature of the counter anions, Br -and PF6 -. It has been found that anions have considerable impacts on the curvature of a lipid membrane, which can either be "kosmotropic" or waterstructure making, or "chaotropic" (structure breaking) effect. Kosmotropic ions generally promote increased Gaussian curvature in lipid cubic phases, causing the lattice cell dimension to shrink. The chaotropic ions promote flatter interfaces with lower curvature, which leads to increased lattice cell dimension. The Br -ion is generally considered to be kosmotropic, while the [PF6] -ion is more chaotropic. However in this case, they have the opposite effects to what expected, with PF6 -promoting a decrease in lattice parameter and then the formation of HII, associated with more highly curved interfaces 55 and Br -doing the opposite.