Fig. 3
Interaction energies and angle-energy curves. a H-O-H angle energy as a function of angle (θ). b YSZ(111) (Y-site)–H2 interaction energy. c Ni(220)–H2 interaction energy. d Ni(111)–YSZ(111) interaction energy. b–d are plotted as a function of distance (r). The interaction energy and angle energy are expressed as relative to the equilibrium structure, through single-point energy calculations by changing (r) and (θ). The insets show the models that are used for the energy calculation. Balls represent hydrogen (H), oxygen (O), zirconium (Zr), yttrium (Y), and nickel (Ni) atoms. YSZ(111) slab with 3-layer Zr/Y and 6-layer O is used in b and the entire structure is shown in d
