Na4UCr3O14 crystallizes in the triclinic P-1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to one O(10), one O(13), one O(2), one O(3), one O(4), one O(6), and one O(7) atom. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(12), one O(14), one O(7), one O(9), and two equivalent O(5) atoms. In the third Na site, Na(3) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(11), one O(13), one O(14), and one O(4) atom. In the fourth Na site, Na(4) is bonded in a 6-coordinate geometry to one O(12), one O(2), one O(5), one O(6), one O(7), and one O(8) atom. U(1) is bonded to one O(1), one O(11), one O(13), one O(3), one O(6), one O(8), and one O(9) atom to form distorted UO7 pentagonal bipyramids that share  a cornercorner with one Cr(1)O4 tetrahedra, corners with two equivalent Cr(2)O4 tetrahedra, and corners with two equivalent Cr(3)O4 tetrahedra. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(11), one O(12), one O(4), and one O(7) atom to form CrO4 tetrahedra that share  a cornercorner with one U(1)O7 pentagonal bipyramid. In the second Cr site, Cr(2) is bonded to one O(1), one O(10), one O(14), and one O(3) atom to form CrO4 tetrahedra that share corners with two equivalent U(1)O7 pentagonal bipyramids. In the third Cr site, Cr(3) is bonded to one O(2), one O(5), one O(8), and one O(9) atom to form CrO4 tetrahedra that share corners with two equivalent U(1)O7 pentagonal bipyramids. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Na(3), one U(1), and one Cr(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Na(4), and one Cr(3) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one U(1), and one Cr(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Na(1), one Na(3), and one Cr(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Na(4), two equivalent Na(2), and one Cr(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Na(1), one Na(4), and one U(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Na(4), and one Cr(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Na(4), one U(1), and one Cr(3) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Na(2), one U(1), and one Cr(3) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(3), and one Cr(2) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Na(3), one U(1), and one Cr(1) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Na(2), one Na(4), and one Cr(1) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Na(1), one Na(3), and one U(1) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal non-coplanar geometry to one Na(2), one Na(3), and one Cr(2) atom.
Na4UCr3O14 crystallizes in the triclinic P-1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to one O(10), one O(13), one O(2), one O(3), one O(4), one O(6), and one O(7) atom. The Na(1)-O(10) bond length is 2.48 Å. The Na(1)-O(13) bond length is 2.42 Å. The Na(1)-O(2) bond length is 2.56 Å. The Na(1)-O(3) bond length is 2.57 Å. The Na(1)-O(4) bond length is 2.60 Å. The Na(1)-O(6) bond length is 2.64 Å. The Na(1)-O(7) bond length is 2.63 Å. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(12), one O(14), one O(7), one O(9), and two equivalent O(5) atoms. The Na(2)-O(12) bond length is 2.53 Å. The Na(2)-O(14) bond length is 2.45 Å. The Na(2)-O(7) bond length is 2.47 Å. The Na(2)-O(9) bond length is 2.51 Å. There is one shorter (2.42 Å) and one longer (2.77 Å) Na(2)-O(5) bond length. In the third Na site, Na(3) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(11), one O(13), one O(14), and one O(4) atom. The Na(3)-O(1) bond length is 2.93 Å. The Na(3)-O(10) bond length is 2.34 Å. The Na(3)-O(11) bond length is 2.54 Å. The Na(3)-O(13) bond length is 2.58 Å. The Na(3)-O(14) bond length is 2.43 Å. The Na(3)-O(4) bond length is 2.36 Å. In the fourth Na site, Na(4) is bonded in a 6-coordinate geometry to one O(12), one O(2), one O(5), one O(6), one O(7), and one O(8) atom. The Na(4)-O(12) bond length is 2.39 Å. The Na(4)-O(2) bond length is 2.45 Å. The Na(4)-O(5) bond length is 2.55 Å. The Na(4)-O(6) bond length is 2.51 Å. The Na(4)-O(7) bond length is 2.39 Å. The Na(4)-O(8) bond length is 2.69 Å. U(1) is bonded to one O(1), one O(11), one O(13), one O(3), one O(6), one O(8), and one O(9) atom to form distorted UO7 pentagonal bipyramids that share  a cornercorner with one Cr(1)O4 tetrahedra, corners with two equivalent Cr(2)O4 tetrahedra, and corners with two equivalent Cr(3)O4 tetrahedra. The U(1)-O(1) bond length is 2.39 Å. The U(1)-O(11) bond length is 2.33 Å. The U(1)-O(13) bond length is 1.83 Å. The U(1)-O(3) bond length is 2.34 Å. The U(1)-O(6) bond length is 1.83 Å. The U(1)-O(8) bond length is 2.34 Å. The U(1)-O(9) bond length is 2.41 Å. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(11), one O(12), one O(4), and one O(7) atom to form CrO4 tetrahedra that share  a cornercorner with one U(1)O7 pentagonal bipyramid. The Cr(1)-O(11) bond length is 1.72 Å. The Cr(1)-O(12) bond length is 1.65 Å. The Cr(1)-O(4) bond length is 1.64 Å. The Cr(1)-O(7) bond length is 1.66 Å. In the second Cr site, Cr(2) is bonded to one O(1), one O(10), one O(14), and one O(3) atom to form CrO4 tetrahedra that share corners with two equivalent U(1)O7 pentagonal bipyramids. The Cr(2)-O(1) bond length is 1.69 Å. The Cr(2)-O(10) bond length is 1.63 Å. The Cr(2)-O(14) bond length is 1.65 Å. The Cr(2)-O(3) bond length is 1.71 Å. In the third Cr site, Cr(3) is bonded to one O(2), one O(5), one O(8), and one O(9) atom to form CrO4 tetrahedra that share corners with two equivalent U(1)O7 pentagonal bipyramids. The Cr(3)-O(2) bond length is 1.64 Å. The Cr(3)-O(5) bond length is 1.65 Å. The Cr(3)-O(8) bond length is 1.70 Å. The Cr(3)-O(9) bond length is 1.69 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Na(3), one U(1), and one Cr(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Na(4), and one Cr(3) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one U(1), and one Cr(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Na(1), one Na(3), and one Cr(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Na(4), two equivalent Na(2), and one Cr(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Na(1), one Na(4), and one U(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Na(4), and one Cr(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Na(4), one U(1), and one Cr(3) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Na(2), one U(1), and one Cr(3) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(3), and one Cr(2) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Na(3), one U(1), and one Cr(1) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Na(2), one Na(4), and one Cr(1) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Na(1), one Na(3), and one U(1) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal non-coplanar geometry to one Na(2), one Na(3), and one Cr(2) atom.