DOI: 10.17188/1739858
title: Materials Data on Na4Hf(S2O9)2 by Materials Project

description: Na4Hf(S2O9)2 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are four inequivalent Na sites. In the first Na site, Na is bonded to six O atoms to form NaO6 octahedra that share corners with five SO4 tetrahedra and an edgeedge with one NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.36–2.64 Å. In the second Na site, Na is bonded to six O atoms to form distorted NaO6 octahedra that share corners with five SO4 tetrahedra and an edgeedge with one NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.37–2.67 Å. In the third Na site, Na is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Na–O bond distances ranging from 2.38–2.78 Å. In the fourth Na site, Na is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Na–O bond distances ranging from 2.39–2.71 Å. Hf is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Hf–O bond distances ranging from 2.11–2.23 Å. There are four inequivalent S sites. In the first S site, S is bonded to four O atoms to form SO4 tetrahedra that share corners with two equivalent NaO6 octahedra. The corner-sharing octahedra tilt angles range from 41–66°. There are a spread of S–O bond distances ranging from 1.45–1.55 Å. In the second S site, S is bonded to four O atoms to form SO4 tetrahedra that share corners with two equivalent NaO6 octahedra. The corner-sharing octahedra tilt angles range from 40–66°. There are a spread of S–O bond distances ranging from 1.45–1.55 Å. In the third S site, S is bonded to four O atoms to form SO4 tetrahedra that share corners with three NaO6 octahedra. The corner-sharing octahedra tilt angles range from 41–59°. There is three shorter (1.47 Å) and one longer (1.56 Å) S–O bond length. In the fourth S site, S is bonded to four O atoms to form SO4 tetrahedra that share corners with three NaO6 octahedra. The corner-sharing octahedra tilt angles range from 39–59°. There are a spread of S–O bond distances ranging from 1.47–1.56 Å. There are eighteen inequivalent O sites. In the first O site, O is bonded in a distorted trigonal planar geometry to one Na, one Hf, and one S atom. In the second O site, O is bonded in a water-like geometry to one Hf and one S atom. In the third O site, O is bonded in a distorted bent 150 degrees geometry to one Na and one S atom. In the fourth O site, O is bonded in a distorted trigonal non-coplanar geometry to two Na and one S atom. In the fifth O site, O is bonded in a distorted trigonal planar geometry to one Na, one Hf, and one S atom. In the sixth O site, O is bonded in a distorted bent 150 degrees geometry to one Na and one S atom. In the seventh O site, O is bonded in a water-like geometry to one Hf and one S atom. In the eighth O site, O is bonded in a 3-coordinate geometry to two Na and one S atom. In the ninth O site, O is bonded in a 1-coordinate geometry to three Na and one S atom. In the tenth O site, O is bonded in a 3-coordinate geometry to two Na and one S atom. In the eleventh O site, O is bonded in a 3-coordinate geometry to two Na and one S atom. In the twelfth O site, O is bonded in a bent 150 degrees geometry to one Hf and one S atom. In the thirteenth O site, O is bonded in a 1-coordinate geometry to three Na and one S atom. In the fourteenth O site, O is bonded in a 3-coordinate geometry to two Na and one S atom. In the fifteenth O site, O is bonded in a 3-coordinate geometry to two Na and one S atom. In the sixteenth O site, O is bonded in a bent 150 degrees geometry to one Hf and one S atom. In the seventeenth O site, O is bonded in a bent 120 degrees geometry to one Na and one Hf atom. In the eighteenth O site, O is bonded in a bent 120 degrees geometry to one Na and one Hf atom.