Loop construction three-electron systems

Generalizing on [12], we construct a loop by using a sequence of three elementary reactions. It is emphasized that the reactions comprising the loop must be elementary ones There should not be any other spin pairing combination that connects two anchors. This ensures that the loop in question is indeed the smallest possible one. Inspection of the loops depicted in Figure 4 shows that the H3 and H4 systems are entirely analogous. We include the H3 system in order to introduce the coordinates spanning the plane in which the loop lies, and as a prototype of all three-electron systems. 

IV. Loop Construction for niotochemical Systems A. Three-Electron Systems... 

---