Materials Data on Sm2Ni2O5 by Materials Project
Sm2Ni2O5 crystallizes in the orthorhombic Ima2 space group. The structure is three-dimensional. Sm3+ is bonded in a 5-coordinate geometry to eight O2- atoms. There are a spread of Sm–O bond distances ranging from 2.32–3.00 Å. There are two inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four equivalent NiO6 octahedra and corners with two equivalent NiO4 tetrahedra. The corner-sharing octahedral tilt angles are 20°. There are a spread of Ni–O bond distances ranging from 1.98–2.17 Å. In the second Ni2+ site, Ni2+ is bonded to four O2- atoms to form NiO4 tetrahedra that share corners with two equivalent NiO6 octahedra and corners with two equivalent NiO4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. There are a spread of Ni–O bond distances ranging from 1.94–2.06 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to four equivalent Sm3+ and two equivalent Ni2+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Sm3+ and two Ni2+ atoms. In the third O2- site, O2- is bonded to two equivalent Sm3+ and two equivalent Ni2+ atoms to form corner-sharing OSm2Ni2 tetrahedra.