Other inorganic Hydrides Neptunium reacts with hydrogen in a similar manner to its neighbor plutonium, forming the hydrides NpH2+x (face-centered cubic) and NpH3 (hexagonal). These are isostructural with the corresponding plutonium hydrides, although unlike PuH2+x, the lattice parameters of NpH2+x become greater as the hydrogen content (x) increases. The hydrides require extreme care in handling as they decompose in a vacuum at 300 °C to form finely divided neptunium metal, which is pyrophoric.Yoshida et al., pp. 722–4.
Other inorganic Hydrides Neptunium reacts with hydrogen in a similar manner to its neighbor plutonium forming the hydrides NpH2+x (face-centered cubic) and NpH3 (hexagonal) These are isostructural with the corresponding plutonium hydrides although unlike PuH2+x the lattice parameters of NpH2+x become greater as the hydrogen content (x) increases The hydrides require extreme care in handling as they decompose in a vacuum at 300 °C to form finely divided neptunium metal which is pyrophoricYoshida et al pp 722–4