DOE OSTI2020
Sr5In2Bi6 crystallizes in the monoclinic Pc space group. The structure is three-dimensional. there are five inequivalent Sr sites. In the first Sr site, Sr is bonded to six Bi atoms to form a mixture of edge and corner-sharing SrBi6 octahedra. The corner-sharing octahedra tilt angles range from 25–45°. There are two shorter (3.40 Å) and four longer (3.41 Å) Sr–Bi bond lengths. In the second Sr site, Sr is bonded to six Bi atoms to form a mixture of distorted edge, corner, and face-sharing SrBi6 octahedra. The corner-sharing octahedra tilt angles range from 25–52°. There are a spread of Sr–Bi bond distances ranging from 3.46–3.49 Å. In the third Sr site, Sr is bonded in a 9-coordinate geometry to two equivalent In and seven Bi atoms. There are one shorter (3.79 Å) and one longer (3.80 Å) Sr–In bond lengths. There are a spread of Sr–Bi bond distances ranging from 3.48–3.70 Å. In the fourth Sr site, Sr is bonded in a 9-coordinate geometry to two equivalent In and seven Bi atoms. There are one shorter (3.79 Å) and one longer (3.80 Å) Sr–In bond lengths. There are a spread of Sr–Bi bond distances ranging from 3.48–3.70 Å. In the fifth Sr site, Sr is bonded to six Bi atoms to form a mixture of distorted edge, corner, and face-sharing SrBi6 octahedra. The corner-sharing octahedra tilt angles range from 25–52°. There are a spread of Sr–Bi bond distances ranging from 3.45–3.49 Å. There are two inequivalent In sites. In the first In site, In is bonded in a 4-coordinate geometry to two equivalent Sr and four Bi atoms. There are three shorter (3.00 Å) and one longer (3.13 Å) In–Bi bond lengths. In the second In site, In is bonded in a 4-coordinate geometry to two equivalent Sr and four Bi atoms. There are three shorter (3.00 Å) and one longer (3.13 Å) In–Bi bond lengths. There are six inequivalent Bi sites. In the first Bi site, Bi is bonded in a 6-coordinate geometry to four Sr and two equivalent In atoms. In the second Bi site, Bi is bonded in a 8-coordinate geometry to six Sr, one In, and one Bi atom. The Bi–Bi bond length is 3.12 Å. In the third Bi site, Bi is bonded in a 6-coordinate geometry to four Sr and two equivalent In atoms. In the fourth Bi site, Bi is bonded in a 8-coordinate geometry to six Sr, one In, and one Bi atom. In the fifth Bi site, Bi is bonded to six Sr and one In atom to form a mixture of distorted edge, corner, and face-sharing BiSr6In pentagonal bipyramids. In the sixth Bi site, Bi is bonded to six Sr and one In atom to form a mixture of distorted edge, corner, and face-sharing BiSr6In pentagonal bipyramids.