Earlier quoted context omitted.
Why is ferrocene ungraphable or in this context unable to be modelled in that way?
I meant metallocenes in general: https://en.wikipedia.org/wiki/Metallocene A metal atom sandwiched between two Cp rings. You _can_ model this as 5 single bonds between each atom of a ring (so 10 total C-M bonds), or you have to have some kind of 'edge' (bond) between the ring as a whole and the metal. The more general issue is that a graph model of a chemical assumes a 'bond' is between exactly two atoms. Three-cente…
But I am just someone who got curious; not even an amateur ^^’