DOE OSTI2020
K3U2O26I7 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are three inequivalent K sites. In the first K site, K is bonded in a 6-coordinate geometry to six O atoms. There are a spread of K–O bond distances ranging from 2.78–3.07 Å. In the second K site, K is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of K–O bond distances ranging from 2.71–3.23 Å. In the third K site, K is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of K–O bond distances ranging from 2.73–3.23 Å. There are two inequivalent U sites. In the first U site, U is bonded in a distorted pentagonal bipyramidal geometry to seven O atoms. There are a spread of U–O bond distances ranging from 1.82–2.43 Å. In the second U site, U is bonded in a distorted pentagonal bipyramidal geometry to seven O atoms. There are a spread of U–O bond distances ranging from 1.83–2.46 Å. There are twenty-six inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to one K and one I atom. The O–I bond length is 1.79 Å. In the second O site, O is bonded in a distorted bent 150 degrees geometry to one U and one I atom. The O–I bond length is 1.87 Å. In the third O site, O is bonded in a bent 150 degrees geometry to one U and one I atom. The O–I bond length is 1.85 Å. In the fourth O site, O is bonded in a 3-coordinate geometry to two equivalent K and one I atom. The O–I bond length is 1.80 Å. In the fifth O site, O is bonded in a bent 120 degrees geometry to one K and one I atom. The O–I bond length is 1.83 Å. In the sixth O site, O is bonded in an L-shaped geometry to two K atoms. In the seventh O site, O is bonded in a 2-coordinate geometry to one K and one I atom. The O–I bond length is 1.84 Å. In the eighth O site, O is bonded in a bent 150 degrees geometry to one K and one I atom. The O–I bond length is 1.80 Å. In the ninth O site, O is bonded in a distorted bent 120 degrees geometry to one U and one I atom. The O–I bond length is 1.86 Å. In the tenth O site, O is bonded in a bent 120 degrees geometry to one U and one I atom. The O–I bond length is 1.86 Å. In the eleventh O site, O is bonded in a bent 120 degrees geometry to one U and one I atom. The O–I bond length is 1.86 Å. In the twelfth O site, O is bonded in a distorted single-bond geometry to two K and one U atom. In the thirteenth O site, O is bonded in a 1-coordinate geometry to one K and one I atom. The O–I bond length is 1.83 Å. In the fourteenth O site, O is bonded in a bent 150 degrees geometry to one U and one I atom. The O–I bond length is 1.86 Å. In the fifteenth O site, O is bonded in a distorted single-bond geometry to one K and two I atoms. There are one shorter (1.82 Å) and one longer (2.60 Å) O–I bond lengths. In the sixteenth O site, O is bonded in a distorted single-bond geometry to one K and one I atom. The O–I bond length is 1.83 Å. In the seventeenth O site, O is bonded in a 1-coordinate geometry to two equivalent K and one I atom. The O–I bond length is 1.81 Å. In the eighteenth O site, O is bonded in a distorted bent 150 degrees geometry to one U and one I atom. The O–I bond length is 1.88 Å. In the nineteenth O site, O is bonded in a distorted single-bond geometry to two K and one U atom. In the twentieth O site, O is bonded in a 2-coordinate geometry to one U and two I atoms. There are one shorter (1.87 Å) and one longer (2.61 Å) O–I bond lengths. In the twenty-first O site, O is bonded in a distorted bent 150 degrees geometry to one U and one I atom. The O–I bond length is 1.89 Å. In the twenty-second O site, O is bonded in a 2-coordinate geometry to one K and one I atom. The O–I bond length is 1.82 Å. In the twenty-third O site, O is bonded in a linear geometry to one U and one I atom. The O–I bond length is 1.85 Å. In the twenty-fourth O site, O is bonded in a distorted bent 120 degrees geometry to one K and one U atom. In the twenty-fifth O site, O is bonded in a 2-coordinate geometry to one K and one I atom. The O–I bond length is 1.83 Å. In the twenty-sixth O site, O is bonded in a distorted single-bond geometry to one K and one U atom. There are seven inequivalent I sites. In the first I site, I is bonded in a 3-coordinate geometry to three O atoms. In the second I site, I is bonded in a trigonal non-coplanar geometry to three O atoms. In the third I site, I is bonded in a 3-coordinate geometry to four O atoms. In the fourth I site, I is bonded in a distorted trigonal non-coplanar geometry to three O atoms. In the fifth I site, I is bonded in a 3-coordinate geometry to three O atoms. In the sixth I site, I is bonded in a trigonal non-coplanar geometry to three O atoms. In the seventh I site, I is bonded in a 5-coordinate geometry to four O atoms.