The table in Figure 2 summarizes the Möbius–Hückel concept. The columns specify whether one has a Möbius or a Hückel structure and the rows specify whether 4n + 2 electrons or 4n electrons are present. Depending on which is present, a Möbius or a Hückel system, one selects the first or the second column. Then depending on the number of electrons present, 4n + 2 or 4n, one selects the first or the second row.<Ref Name=HEZ1971/>