Figure 1.

United-atom to coarse-grained mapping schemes for POPC and cholesterol. For each mapping, the polygon indicates a group of atoms that is mapped to a coarse-grained particle. For distance and angle calculations, the position of the coarse-grained particle is calculated by a weighted average of the positions of its constituent atoms. We assign a weight of 1.0 to an atom that belongs to only one coarse-grained particle and a weight of 1/N to an atom that is shared between N particles. The original UA-to-CG mappings of MARTINI are approximately illustrated in Marrink et al.²⁸