Materials Data on Ca2BiAsO6 by Materials Project
Ca2BiAsO6 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.31–2.82 Å. Bi3+ is bonded in a 4-coordinate geometry to four equivalent O2- atoms. There are two shorter (2.23 Å) and two longer (2.27 Å) Bi–O bond lengths. As5+ is bonded in a tetrahedral geometry to four O2- atoms. There is one shorter (1.72 Å) and three longer (1.73 Å) As–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Ca2+ and two equivalent Bi3+ atoms to form a mixture of corner and edge-sharing OCa2Bi2 tetrahedra. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ca2+ and one As5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ca2+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to four equivalent Ca2+ and one As5+ atom.