The heat of dissociation of oxygen

It has recently been suggested by Gerhard Herzberg (Zeits. f. phys. Chem. 4B, 223 (1929)) that the currently accepted value for the heat of dissociation of oxygen is too high. Herzberg concludes that the correct value is not 7.0 volts, but somewhere between 5 and 6 volts; the basis for the conclusion is a re-interpretation of the Lyman-Runge bands on the basis of a theory developed by Wigner and Witmer.