The reasoning we have just demonstrated up to here could be extended to longer polyiodides, yet with I7 -we already have the onset of structural isomers, i.e. branched species, like pyramidal I7 -, which can be considered as 3 fused 3c-4e systems with a single atom acting as the pyramid vertex and three branches of two atoms so that all branches are characterized by linear 3c-4e bonds. One may thus expect I9 -to be the next logical stable polyiodide in the series, although its rare reports only saw it as a branched rather than a linear species. If it were assumed as linear, our reasoning suggests that bending would occur at atoms 3, 5, and 7, i.e. the existence of the anion as a formal series of 4 fused 3c-4e systems held together by weaker (intermediate between 2c-2e and 2c-1e) bonds. It should be noticed that increasing the number of formally fused 3c-4e systems (e.g. moving from I5 -to I7 -) already results in significant lengthening of longest bond in the chain, meaning that an anion of formula I9 -(much like I7 -) would likely propend for branched geometries instead. These and other complex systems with more I atoms are beyond the scope of present discussion.