Materials Data on Ca2V2O9 by Materials Project
Ca2V2O9 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Ca sites. In the first Ca site, Ca is bonded in a 6-coordinate geometry to eight O atoms. There are a spread of Ca–O bond distances ranging from 2.33–3.04 Å. In the second Ca site, Ca is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Ca–O bond distances ranging from 2.33–3.00 Å. There are two inequivalent V sites. In the first V site, V is bonded to four O atoms to form corner-sharing VO4 tetrahedra. There are a spread of V–O bond distances ranging from 1.68–1.82 Å. In the second V site, V is bonded to four O atoms to form corner-sharing VO4 tetrahedra. There are a spread of V–O bond distances ranging from 1.71–1.80 Å. There are nine inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to two V atoms. In the second O site, O is bonded in a distorted trigonal non-coplanar geometry to two Ca and one V atom. In the third O site, O is bonded in a bent 150 degrees geometry to one Ca and one V atom. In the fourth O site, O is bonded in a 1-coordinate geometry to three Ca and one V atom. In the fifth O site, O is bonded in a distorted T-shaped geometry to two Ca and one V atom. In the sixth O site, O is bonded in a distorted T-shaped geometry to two Ca and one V atom. In the seventh O site, O is bonded in a 4-coordinate geometry to three Ca and one V atom. In the eighth O site, O is bonded in a bent 120 degrees geometry to one Ca and one O atom. The O–O bond length is 1.23 Å. In the ninth O site, O is bonded in a distorted bent 120 degrees geometry to one Ca and one O atom.