A very general set of electron counting rules that predict which structures of polyhedral molecules are stable. These rules can be considered to be extensions and generalizations of the Hückel rule and Wade’s rules. They were formulated by Eluvathingal Devassy Jemmis (1951– ) in 2001.

Despite the title, there are actually four quantities m,n,o,p in these rules, where m is the number of polyhedra, n is the number of vertices, o is the number of single-atom bridges between two polyhedra, and p is the number of vertices missing in the polyhedra. If N is the number of electron pairs on the ‘skeleton’ of the polyhedra, then for a stable system m + n + o + p = N. For example, in the case of B₁₂ H₁₂²⁻, which has the shape of an icosahedron and is the most stable borane, m = 1, n = 12, o = 0, p = 0, giving a total of 13. The number N of electron pairs in this polyhedron is also 13, thus explaining its stability.