A potentially bicycloaromatic species is the bicyclo[2.2.1]heptadienyl cation (C7H7 + ) as it has four -electrons and m = 7. Conversely, bicyclo[3.2.2]nonatrienyl (C9H9 + ) with m = 9 should in theory be bicycloantiaromatic as it has in total six π-electrons and the even-odd bridge interaction is destabilizing as it involves four π-electrons. Based on the original definition of bicycloaromaticity, it is clear that 2 and 3 do not satisfy the criteria for bicycloaromaticity as (i) they possess 42 π-electrons (a 4n + 2 number corresponding to bicycloantiaromaticity), (ii) the three bridges (ribbons) are not separate from each other as they all interact conjugatively with the two bridgehead atoms which are sp 2 instead of sp 3 hybridized, and (iii) all bridges have even numbers of atoms in the -conjugated paths (16, 16 and 8) (Figure ). With two bridgehead atoms this implies that they are not CmHm compounds with m odd as the sum equals 42 (16 + 16 + 8 + 2). Thus, the description of bicycloaromaticity by Kim and co-workers as a concept where "two (or more) potentially aromatic circuits are contained within the same non-planar molecular framework and share the same  electrons" is not in line with the original definition (Figure ).