Table 1. Theoretical reactivity of the (0001) surface.

Energy (eV)	Reaction a	Mn2N	Sr2N
ΔGvac		0.50	1.52
ΔGvac, bulk		0.82	1.88
ΔGads[H*]		–0.79	–0.45
ΔGads[2H*] b	2* + H2 = 2H*	–1.30	–1.10
ΔGads[H2O*]	* + H2O = H2O*	— c	–0.64
ΔGads[OH*]		–1.47	–2.20
ΔGads[OH*, H*]	2* + H2O = OH* + H*	–1.81	–2.73

^aLat, s, and ss mark the lattice nitrogen, surface and subsurface.

^bDissociative hydrogen adsorption at increased surface coverage of 1/2 ML H*.

^cH₂O dissociated to OH* and H*.