DOE OSTI2020
Eu(O3I)3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Eu3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Eu–O bond distances ranging from 2.39–2.97 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Eu3+ and one I5+ atom. The O–I bond length is 1.86 Å. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Eu3+ and one I5+ atom. The O–I bond length is 1.83 Å. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Eu3+ and one I5+ atom. The O–I bond length is 1.84 Å. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Eu3+ and one I5+ atom. The O–I bond length is 1.83 Å. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Eu3+ and two I5+ atoms. There are one shorter (1.85 Å) and one longer (2.89 Å) O–I bond lengths. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Eu3+ and one I5+ atom. The O–I bond length is 1.83 Å. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to two I5+ atoms. There are one shorter (1.83 Å) and one longer (2.81 Å) O–I bond lengths. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent I5+ atoms. There are one shorter (1.86 Å) and one longer (2.43 Å) O–I bond lengths. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Eu3+ and one I5+ atom. The O–I bond length is 1.84 Å. There are three inequivalent I5+ sites. In the first I5+ site, I5+ is bonded in a 6-coordinate geometry to six O2- atoms. In the second I5+ site, I5+ is bonded in a 3-coordinate geometry to three O2- atoms. In the third I5+ site, I5+ is bonded in a 3-coordinate geometry to three O2- atoms.