water in contact with a polar interface representing a layer of cholesterol molecules. X-ray
diffraction data of a cholesterol monohydrate crystal were used to build up a model for a
cholesterol monolayer consisting of fixed cholesterol fragments with an hydrophilic head
(Fig. 1). The polar surface was taken as a grid of isolated hydroxyl groups. Special boundary
conditions were introduced to represent the triclinic symmetry of the crystal in an orthogonal …