Materials Data on Na2Eu2Ti2O9 by Materials Project
Na2Eu2Ti2O9 crystallizes in the orthorhombic Imm2 space group. The structure is three-dimensional. Na is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Na–O bond distances ranging from 2.39–2.78 Å. Eu is bonded in a 9-coordinate geometry to nine O atoms. There are a spread of Eu–O bond distances ranging from 2.28–2.66 Å. Ti is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Ti–O bond distances ranging from 1.75–1.94 Å. There are five inequivalent O sites. In the first O site, O is bonded in a 1-coordinate geometry to four equivalent Na and one Ti atom. In the second O site, O is bonded in a 1-coordinate geometry to five equivalent Eu atoms. In the third O site, O is bonded to two equivalent Eu and two equivalent Ti atoms to form distorted corner-sharing OEu2Ti2 trigonal pyramids. In the fourth O site, O is bonded in a 4-coordinate geometry to two equivalent Eu and two equivalent Ti atoms. In the fifth O site, O is bonded in a square co-planar geometry to four equivalent Na atoms.