Materials Data on Sm3TaO7 by Materials Project

Sm3TaO7 crystallizes in the orthorhombic Cmme space group. The structure is three-dimensional. there are two inequivalent Sm3+ sites. In the first Sm3+ site, Sm3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Sm–O bond distances ranging from 2.15–2.58 Å. In the second Sm3+ site, Sm3+ is bonded in a distorted hexagonal planar geometry to six O2- atoms. There are two shorter (2.33 Å) and four longer (2.36 Å) Sm–O bond lengths. Ta5+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.14 Å) and four longer (2.23 Å) Ta–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sm3+ and two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded to three Sm3+ and one Ta5+ atom to form a mixture of distorted corner and edge-sharing OSm3Ta tetrahedra. In the third O2- site, O2- is bonded to four Sm3+ atoms to form a mixture of corner and edge-sharing OSm4 tetrahedra.