Materials Data on Sm3Co29(Si2B5)2 by Materials Project
CoSm3Co28(B5Si2)2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional and consists of two cobalt molecules and one Sm3Co28(B5Si2)2 framework. In the Sm3Co28(B5Si2)2 framework, there are two inequivalent Sm3+ sites. In the first Sm3+ site, Sm3+ is bonded in a 4-coordinate geometry to four equivalent Si4- atoms. All Sm–Si bond lengths are 3.20 Å. In the second Sm3+ site, Sm3+ is bonded in a 8-coordinate geometry to four equivalent Si4- atoms. All Sm–Si bond lengths are 3.25 Å. There are six inequivalent Co+1.28+ sites. In the first Co+1.28+ site, Co+1.28+ is bonded in a distorted rectangular see-saw-like geometry to three B3- and one Si4- atom. There are two shorter (2.05 Å) and one longer (2.12 Å) Co–B bond lengths. The Co–Si bond length is 2.33 Å. In the second Co+1.28+ site, Co+1.28+ is bonded in a distorted T-shaped geometry to three B3- and one Si4- atom. There are one shorter (2.09 Å) and two longer (2.13 Å) Co–B bond lengths. The Co–Si bond length is 2.56 Å. In the third Co+1.28+ site, Co+1.28+ is bonded in a distorted single-bond geometry to one B3- and three equivalent Si4- atoms. The Co–B bond length is 1.91 Å. There are one shorter (2.39 Å) and two longer (2.42 Å) Co–Si bond lengths. In the fourth Co+1.28+ site, Co+1.28+ is bonded in a distorted rectangular see-saw-like geometry to three B3- and one Si4- atom. There are a spread of Co–B bond distances ranging from 2.06–2.12 Å. The Co–Si bond length is 2.35 Å. In the fifth Co+1.28+ site, Co+1.28+ is bonded in a distorted bent 150 degrees geometry to two B3- and two equivalent Si4- atoms. Both Co–B bond lengths are 2.13 Å. Both Co–Si bond lengths are 2.67 Å. In the sixth Co+1.28+ site, Co+1.28+ is bonded in a square co-planar geometry to four B3- atoms. There are a spread of Co–B bond distances ranging from 2.06–2.11 Å. There are four inequivalent B3- sites. In the first B3- site, B3- is bonded in a 9-coordinate geometry to eight Co+1.28+ and one B3- atom. The B–B bond length is 2.04 Å. In the second B3- site, B3- is bonded in a 7-coordinate geometry to seven Co+1.28+ atoms. In the third B3- site, B3- is bonded in a 9-coordinate geometry to eight Co+1.28+ and one B3- atom. The B–B bond length is 2.00 Å. In the fourth B3- site, B3- is bonded in a 9-coordinate geometry to eight Co+1.28+ and one B3- atom. Si4- is bonded to three Sm3+ and nine Co+1.28+ atoms to form a mixture of distorted corner, edge, and face-sharing SiSm3Co9 cuboctahedra.