DOE OSTI2020
Tb2Sb5 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are four inequivalent Tb3+ sites. In the first Tb3+ site, Tb3+ is bonded in a 9-coordinate geometry to nine Sb+1.20- atoms. There are a spread of Tb–Sb bond distances ranging from 3.14–3.34 Å. In the second Tb3+ site, Tb3+ is bonded in a 9-coordinate geometry to ten Sb+1.20- atoms. There are a spread of Tb–Sb bond distances ranging from 3.19–3.89 Å. In the third Tb3+ site, Tb3+ is bonded in a 9-coordinate geometry to nine Sb+1.20- atoms. There are a spread of Tb–Sb bond distances ranging from 3.20–3.36 Å. In the fourth Tb3+ site, Tb3+ is bonded in a 9-coordinate geometry to nine Sb+1.20- atoms. There are a spread of Tb–Sb bond distances ranging from 3.12–3.36 Å. There are ten inequivalent Sb+1.20- sites. In the first Sb+1.20- site, Sb+1.20- is bonded in a 6-coordinate geometry to three Tb3+ and three Sb+1.20- atoms. There are one shorter (2.89 Å) and two longer (3.03 Å) Sb–Sb bond lengths. In the second Sb+1.20- site, Sb+1.20- is bonded in a 8-coordinate geometry to four Tb3+ and four Sb+1.20- atoms. Both Sb–Sb bond lengths are 3.16 Å. In the third Sb+1.20- site, Sb+1.20- is bonded in a 7-coordinate geometry to five Tb3+ and two equivalent Sb+1.20- atoms. In the fourth Sb+1.20- site, Sb+1.20- is bonded in a 6-coordinate geometry to three Tb3+ and three Sb+1.20- atoms. There are two shorter (2.95 Å) and one longer (3.45 Å) Sb–Sb bond lengths. In the fifth Sb+1.20- site, Sb+1.20- is bonded in a 7-coordinate geometry to three Tb3+ and four Sb+1.20- atoms. There are two shorter (2.99 Å) and two longer (3.20 Å) Sb–Sb bond lengths. In the sixth Sb+1.20- site, Sb+1.20- is bonded in a 8-coordinate geometry to four Tb3+ and four Sb+1.20- atoms. There are two shorter (2.99 Å) and two longer (3.08 Å) Sb–Sb bond lengths. In the seventh Sb+1.20- site, Sb+1.20- is bonded in a 8-coordinate geometry to four Tb3+ and four Sb+1.20- atoms. In the eighth Sb+1.20- site, Sb+1.20- is bonded in a 8-coordinate geometry to four Tb3+ and four Sb+1.20- atoms. Both Sb–Sb bond lengths are 3.21 Å. In the ninth Sb+1.20- site, Sb+1.20- is bonded to six Tb3+ atoms to form distorted face-sharing SbTb6 pentagonal pyramids. In the tenth Sb+1.20- site, Sb+1.20- is bonded in a 7-coordinate geometry to one Tb3+ and six Sb+1.20- atoms. Both Sb–Sb bond lengths are 3.46 Å.