Materials Data on BaCaSiO4 by Materials Project
BaCaSiO4 crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 1-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.46–3.02 Å. In the second Ba2+ site, Ba2+ is bonded in a 1-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.56–2.96 Å. There are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ca–O bond distances ranging from 2.41–2.81 Å. In the second Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. There are three shorter (2.32 Å) and three longer (2.72 Å) Ca–O bond lengths. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the second Si4+ site, Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There is one shorter (1.62 Å) and three longer (1.66 Å) Si–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one Ba2+, three equivalent Ca2+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Ba2+, two equivalent Ca2+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Ba2+, two equivalent Ca2+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Ba2+, two equivalent Ca2+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to three Ba2+, two equivalent Ca2+, and one Si4+ atom.