Materials Data on Sm2Ta2Cl2O7 by Materials Project
Sm2Ta2Cl2O7 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Sm3+ is bonded in a 9-coordinate geometry to six O2- and three equivalent Cl1- atoms. There are a spread of Sm–O bond distances ranging from 2.37–2.60 Å. There are two shorter (2.87 Å) and one longer (2.88 Å) Sm–Cl bond lengths. Ta5+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 0–15°. There are a spread of Ta–O bond distances ranging from 1.92–2.26 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to one Sm3+ and two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sm3+ and two equivalent Ta5+ atoms. In the third O2- site, O2- is bonded in a linear geometry to two equivalent Ta5+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Sm3+ and one Ta5+ atom. Cl1- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Sm3+ atoms.