DOE OSTI2020
(CaO2)2Ca8V5Fe15(BiO22)2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional and consists of two calcium hydrate molecules and one Ca8V5Fe15(BiO22)2 framework. In the Ca8V5Fe15(BiO22)2 framework, there are four inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a bent 150 degrees geometry to two O2- atoms. There is one shorter (1.39 Å) and one longer (1.48 Å) Ca–O bond length. In the second Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to one V5+, one Bi3+, and four O2- atoms. The Ca–V bond length is 2.21 Å. The Ca–Bi bond length is 2.20 Å. There are a spread of Ca–O bond distances ranging from 2.19–2.68 Å. In the third Ca2+ site, Ca2+ is bonded in a 2-coordinate geometry to one V5+, one Fe3+, and four O2- atoms. The Ca–V bond length is 2.23 Å. The Ca–Fe bond length is 2.21 Å. There are a spread of Ca–O bond distances ranging from 2.01–2.43 Å. In the fourth Ca2+ site, Ca2+ is bonded in a 2-coordinate geometry to one V5+ and four O2- atoms. The Ca–V bond length is 2.24 Å. There are a spread of Ca–O bond distances ranging from 1.81–2.48 Å. There are five inequivalent V5+ sites. In the first V5+ site, V5+ is bonded in a linear geometry to two equivalent O2- atoms. Both V–O bond lengths are 1.10 Å. In the second V5+ site, V5+ is bonded in a distorted octahedral geometry to two equivalent Ca2+ and four O2- atoms. There are two shorter (2.04 Å) and two longer (2.42 Å) V–O bond lengths. In the third V5+ site, V5+ is bonded in a 6-coordinate geometry to two equivalent Bi3+ and four O2- atoms. Both V–Bi bond lengths are 2.31 Å. There are two shorter (2.04 Å) and two longer (2.42 Å) V–O bond lengths. In the fourth V5+ site, V5+ is bonded in a 2-coordinate geometry to two equivalent Ca2+ and four O2- atoms. There is two shorter (1.71 Å) and two longer (2.01 Å) V–O bond length. In the fifth V5+ site, V5+ is bonded in a 2-coordinate geometry to two equivalent Ca2+ and four O2- atoms. There is two shorter (1.69 Å) and two longer (2.01 Å) V–O bond length. There are nine inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded in a distorted L-shaped geometry to three O2- atoms. There are a spread of Fe–O bond distances ranging from 1.49–2.36 Å. In the second Fe3+ site, Fe3+ is bonded in a 2-coordinate geometry to two O2- atoms. There is one shorter (1.53 Å) and one longer (1.64 Å) Fe–O bond length. In the third Fe3+ site, Fe3+ is bonded in a 2-coordinate geometry to two O2- atoms. There is one shorter (1.52 Å) and one longer (1.67 Å) Fe–O bond length. In the fourth Fe3+ site, Fe3+ is bonded in a 1-coordinate geometry to one Ca2+ and three O2- atoms. There are a spread of Fe–O bond distances ranging from 1.54–2.13 Å. In the fifth Fe3+ site, Fe3+ is bonded in a distorted L-shaped geometry to three O2- atoms. There are a spread of Fe–O bond distances ranging from 1.47–2.35 Å. In the sixth Fe3+ site, Fe3+ is bonded in a linear geometry to two equivalent O2- atoms. Both Fe–O bond lengths are 2.30 Å. In the seventh Fe3+ site, Fe3+ is bonded in a 1-coordinate geometry to two O2- atoms. There is one shorter (1.54 Å) and one longer (1.88 Å) Fe–O bond length. In the eighth Fe3+ site, Fe3+ is bonded in a linear geometry to two equivalent O2- atoms. Both Fe–O bond lengths are 1.17 Å. In the ninth Fe3+ site, Fe3+ is bonded in a linear geometry to two equivalent O2- atoms. Both Fe–O bond lengths are 2.29 Å. Bi3+ is bonded in a 6-coordinate geometry to one Ca2+, one V5+, and four O2- atoms. There are a spread of Bi–O bond distances ranging from 2.21–2.70 Å. There are twenty-two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two Ca2+ atoms. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one V5+, one Fe3+, and one Bi3+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Fe3+, one Bi3+, and two O2- atoms. Both O–O bond lengths are 1.85 Å. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+, one V5+, and one O2- atom. The O–O bond length is 1.87 Å. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Ca2+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to one Ca2+, one Fe3+, and two O2- atoms. The O–O bond length is 1.85 Å. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to one Ca2+, one V5+, and one Fe3+ atom. In the eighth O2- site, O2- is bonded in a single-bond geometry to one Fe3+ atom. In the ninth O2- site, O2- is bonded in a distorted single-bond geometry to one Ca2+ and one Fe3+ atom. In the tenth O2- site, O2- is bonded in a distorted water-like geometry to two Fe3+ atoms. In the eleventh O2- site, O2- is bonded in a single-bond geometry to one Fe3+ atom. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, one V5+, one Fe3+, and one O2- atom. The O–O bond length is 1.61 Å. In the thirteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one V5+ and one Fe3+ atom. In the fourteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+, one V5+, and one O2- atom. In the fifteenth O2- site, O2- is bonded in a distorted single-bond geometry to two Fe3+ and one O2- atom. In the sixteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, one V5+, one Fe3+, and one O2- atom. The O–O bond length is 1.64 Å. In the seventeenth O2- site, O2- is bonded in a distorted single-bond geometry to two Fe3+ and one O2- atom. In the eighteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Fe3+ and one Bi3+ atom. In the nineteenth O2- site, O2- is bonded in a single-bond geometry to one Ca2+ and one Bi3+ atom. In the twentieth O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+, one V5+, and one O2- atom. In the twenty-first O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+ and one Fe3+ atom. In the twenty-second O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+, one V5+, and one O2- atom.