It only looks like a protonic orbital. But it is a H*, a proton plus an electron in a shrunken orbit bound to 56Fe, because the chemistry still shows Iron, with some disturbance in the orbits and not 57Co.
Continuing, inspired by Jacques Dufour's notion, and Wyttenbach's worthy critiques:
Does it even look like one? I suspect actual nuclear protonic orbitals may be considered NO Larger than 1/1837th of any outer electronic orbital. By the muonic analogy given earlier (muon 207 times electron mass, radius of muonic orbital 1/207th that of an electron. https://doi.org/10.1134%2FS106377961102002X).
Keeping in mind that hydrogen atoms, ions and protons with or without neutrons are unique chemically and physically, [I point out the obvious to many here, but want to keep others with the discussion.]
By having or capturing a conduction band electron, a/an hydride / deuteride negative ion--- that is an effective H-, proton with two electrons, one or both borrowed at some electronic level from a transition metal (Fe, Pd, V, Mo, Mn, Tl etc) might find a comfortable, or confused interfacial "orbital" to at least briefly occupy, since that proton comes already shielded. Can coincindent occupation of an orbital lead to proton / deuteron fusion? Could coincident hydride / deuteride orbitals and the differing masses greatly increase the normally infinitesimal cross section for fusion? And would the conduction band (?), faraday screened, electronic milieu provide the putative gamma screening and effective thermalization??
Note for comparison: the lifetime of the free muon ( t1/2 ~2 microseconds, https://www.sciencedaily.com/r…/2011/01/110125131450.htm)
