Materials Data on Ca2Bi7 by Materials Project
Ca2Bi7 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of one Ca2Bi7 sheet oriented in the (0, 0, 1) direction. Ca is bonded in a 12-coordinate geometry to nine Bi atoms. There are a spread of Ca–Bi bond distances ranging from 3.38–3.55 Å. There are three inequivalent Bi sites. In the first Bi site, Bi is bonded to six equivalent Ca and six Bi atoms to form distorted edge-sharing BiCa6Bi6 cuboctahedra. There are two shorter (3.44 Å) and four longer (3.52 Å) Bi–Bi bond lengths. In the second Bi site, Bi is bonded in a 9-coordinate geometry to two equivalent Ca and one Bi atom. In the third Bi site, Bi is bonded in a 9-coordinate geometry to two equivalent Ca and one Bi atom.
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