Then, each net in the structure is identified by its dimensionality (one, two or threedimensional) and a unique identifier, its topological genome: it is a finite series of integers, such as 3 1 2 0 0 0 1 2 0 0 1 1 2 0 1 0 1 2 1 0 0 for the diamondoid (dia) net. We note that some nets are unstable, i.e., they cannot be assigned a unique genome: this happens when at least two vertices, in their equilibrium placement, have the same position -we refer the interested reader to Ref. 11 for more details on this. This accounted for 8871 of the structures studied, most of them two-dimensional, and because we cannot ensure that they are uniquely assigned to a given net genome, they were excluded from our current analysis.