K4Gd2C3O9F4 crystallizes in the monoclinic C2 space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to one O(1), one O(3), one O(4), one O(5), two equivalent O(2), one F(2), and two equivalent F(1) atoms. In the second K site, K(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), and two equivalent F(1) atoms. In the third K site, K(3) is bonded in a distorted hexagonal bipyramidal geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent F(1) atoms. Gd(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(5), two equivalent O(4), one F(1), and two equivalent F(2) atoms. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(4) atom. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(5) and two equivalent O(3) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(3), one Gd(1), and one C(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one K(3), two equivalent K(1), one Gd(1), and one C(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(3), one Gd(1), and one C(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one K(1), one K(2), two equivalent Gd(1), and one C(1) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to two equivalent K(1), two equivalent Gd(1), and one C(2) atom. There are two inequivalent F sites. In the first F site, F(1) is bonded to one K(2), one K(3), two equivalent K(1), and one Gd(1) atom to form distorted corner-sharing FK4Gd trigonal bipyramids. In the second F site, F(2) is bonded in a trigonal non-coplanar geometry to one K(1) and two equivalent Gd(1) atoms.
K4Gd2C3O9F4 crystallizes in the monoclinic C2 space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to one O(1), one O(3), one O(4), one O(5), two equivalent O(2), one F(2), and two equivalent F(1) atoms. The K(1)-O(1) bond length is 3.23 Å. The K(1)-O(3) bond length is 2.80 Å. The K(1)-O(4) bond length is 2.95 Å. The K(1)-O(5) bond length is 2.88 Å. There is one shorter (2.87 Å) and one longer (3.04 Å) K(1)-O(2) bond length. The K(1)-F(2) bond length is 2.56 Å. There is one shorter (2.88 Å) and one longer (2.92 Å) K(1)-F(1) bond length. In the second K site, K(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), and two equivalent F(1) atoms. Both K(2)-O(1) bond lengths are 2.70 Å. Both K(2)-O(3) bond lengths are 3.07 Å. Both K(2)-O(4) bond lengths are 2.87 Å. Both K(2)-F(1) bond lengths are 2.95 Å. In the third K site, K(3) is bonded in a distorted hexagonal bipyramidal geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent F(1) atoms. Both K(3)-O(1) bond lengths are 2.85 Å. Both K(3)-O(2) bond lengths are 2.91 Å. Both K(3)-O(3) bond lengths are 2.86 Å. Both K(3)-F(1) bond lengths are 2.70 Å. Gd(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(5), two equivalent O(4), one F(1), and two equivalent F(2) atoms. The Gd(1)-O(1) bond length is 2.54 Å. The Gd(1)-O(2) bond length is 2.44 Å. The Gd(1)-O(3) bond length is 2.46 Å. The Gd(1)-O(5) bond length is 2.67 Å. There is one shorter (2.61 Å) and one longer (2.70 Å) Gd(1)-O(4) bond length. The Gd(1)-F(1) bond length is 2.25 Å. There is one shorter (2.32 Å) and one longer (2.36 Å) Gd(1)-F(2) bond length. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(4) atom. The C(1)-O(1) bond length is 1.28 Å. The C(1)-O(2) bond length is 1.30 Å. The C(1)-O(4) bond length is 1.31 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(5) and two equivalent O(3) atoms. The C(2)-O(5) bond length is 1.29 Å. Both C(2)-O(3) bond lengths are 1.30 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(3), one Gd(1), and one C(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one K(3), two equivalent K(1), one Gd(1), and one C(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(3), one Gd(1), and one C(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one K(1), one K(2), two equivalent Gd(1), and one C(1) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to two equivalent K(1), two equivalent Gd(1), and one C(2) atom. There are two inequivalent F sites. In the first F site, F(1) is bonded to one K(2), one K(3), two equivalent K(1), and one Gd(1) atom to form distorted corner-sharing FK4Gd trigonal bipyramids. In the second F site, F(2) is bonded in a trigonal non-coplanar geometry to one K(1) and two equivalent Gd(1) atoms.