Combined Distribution Function (CDF) are two-or higher-dimensional histograms over certain selected scalar quantities, which are evaluated over all pairs (or n-tuples) of selected molecule in the system. In Figure , a CDF is given that relates the distance between two [EMI] + geometric ring centers (X-axis) to the angle between the ring normal vector of the one cation and the connection line between both ring centers (Y-axis). Angles close to 0• and 180• indicate that one ring is directly located on top of the other, whereas angles around 90• signalize that the ring is found in the ring plane of the other ring. For system A, it can be seen that the rings are around 0-30° for short distances around 200-500 pm and 180° for around 500pm which shows that the