Creation of Reactive Volumes through Geometric Tolerances: This graphic is a projection of the three-dimensional system in two dimensions and hence only uses one torsional angle instead of two. Given the molecule graph of the two blue elementary molecules, a reaction with a third, yellow molecule would ideally occur under an angle of α and the distance of d (the sum of both involved site lengths). But since the exact combination of angles and distances would hardly ever be satisfied in the time-discretized simulation, the bond tolerances t
were introduced. They describe a volume V
(or an area in this two dimensional graphic) that can accommodate a possible partner for a reaction. Here, V
is only shown from the blue molecule graph's point of view, while the yellow molecules would create another reactive volume. A reaction between two molecules is only allowed if they both are situated in each other's reactive volumes.