Materials Data on Tb5(SiSb)2 by Materials Project
Tb5Si2Sb2 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. there are two inequivalent Tb sites. In the first Tb site, Tb is bonded to three Si and three Sb atoms to form distorted TbSi3Sb3 pentagonal pyramids that share corners with three equivalent TbSi4Sb2 octahedra, corners with ten equivalent TbSi3Sb3 pentagonal pyramids, edges with seven equivalent TbSi3Sb3 pentagonal pyramids, faces with two equivalent TbSi4Sb2 octahedra, and faces with two equivalent TbSi3Sb3 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 36–41°. There are a spread of Tb–Si bond distances ranging from 2.99–3.04 Å. There are two shorter (3.16 Å) and one longer (3.17 Å) Tb–Sb bond lengths. In the second Tb site, Tb is bonded to four Si and two equivalent Sb atoms to form TbSi4Sb2 octahedra that share corners with four equivalent TbSi4Sb2 octahedra, corners with twelve equivalent TbSi3Sb3 pentagonal pyramids, and faces with eight equivalent TbSi3Sb3 pentagonal pyramids. The corner-sharing octahedral tilt angles are 53°. There are two shorter (3.10 Å) and two longer (3.12 Å) Tb–Si bond lengths. Both Tb–Sb bond lengths are 3.14 Å. There are three inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to eight Tb and one Si atom. The Si–Si bond length is 2.80 Å. In the second Si site, Si is bonded in a 9-coordinate geometry to eight Tb and one Si atom. There are a spread of Si–Tb bond distances ranging from 2.99–3.04 Å. In the third Si site, Si is bonded in a 9-coordinate geometry to eight Tb and one Si atom. The Si–Si bond length is 2.80 Å. There are two inequivalent Sb sites. In the first Sb site, Sb is bonded to seven Tb atoms to form a mixture of distorted corner and edge-sharing SbTb7 pentagonal bipyramids. In the second Sb site, Sb is bonded to seven Tb atoms to form a mixture of distorted corner and edge-sharing SbTb7 pentagonal bipyramids. The Sb–Tb bond length is 3.14 Å.