One further point relative to... "it would surprise no one to learn that a nickel version is also used (nominally NiOOH)."
As mentioned before wrt Rydberg holes in nickel and iron, the combination of the two (found in the Rossi reactor as well) is especially energetic for ground state redundancy, since all of these deeper levels are covered: 54.4 eV 108.5 eV 190.4 eV 299.2 eV And the interesting deduction from those values is that average gain for the proton of NiOOH would be in the previously mentioned range - where the bulk material would appear to actually have about 50 time more energy than chemical, which was similar to a claim by some proponents of "ballotechnics"... Of interest in this regard is this report: http://www.proton21.com.ua/publ/Proton21_Energy_EN.pdf
