NaNb3(TeO4)4 crystallizes in the monoclinic P2_1/m space group. Na(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(4), two equivalent O(7), and two equivalent O(9) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(8), and one O(9) atom to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 15-36°. In the second Nb site, Nb(2) is bonded to two equivalent O(10), two equivalent O(11), and two equivalent O(8) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 15-32°. There are four inequivalent Te sites. In the first Te site, Te(1) is bonded in a 3-coordinate geometry to one O(6) and two equivalent O(10) atoms. In the second Te site, Te(2) is bonded in a distorted rectangular see-saw-like geometry to one O(6), one O(7), and two equivalent O(3) atoms. In the third Te site, Te(3) is bonded in a distorted rectangular see-saw-like geometry to one O(4), one O(7), and two equivalent O(9) atoms. In the fourth Te site, Te(4) is bonded in a 3-coordinate geometry to one O(4) and two equivalent O(2) atoms. There are eleven inequivalent O sites. In the first O site, O(10) is bonded in a bent 150 degrees geometry to one Nb(2) and one Te(1) atom. In the second O site, O(11) is bonded in a bent 150 degrees geometry to two equivalent Nb(2) atoms. In the third O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Nb(1) atoms. In the fourth O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Nb(1), and one Te(4) atom. In the fifth O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Nb(1) and one Te(2) atom. In the sixth O site, O(4) is bonded to two equivalent Na(1), one Te(3), and one Te(4) atom to form a mixture of distorted edge and corner-sharing ONa2Te2 tetrahedra. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to two equivalent Nb(1) atoms. In the eighth O site, O(6) is bonded in a bent 150 degrees geometry to one Te(1) and one Te(2) atom. In the ninth O site, O(7) is bonded to two equivalent Na(1), one Te(2), and one Te(3) atom to form a mixture of distorted edge and corner-sharing ONa2Te2 tetrahedra. In the tenth O site, O(8) is bonded in a linear geometry to one Nb(1) and one Nb(2) atom. In the eleventh O site, O(9) is bonded in a distorted trigonal non-coplanar geometry to one Na(1), one Nb(1), and one Te(3) atom.
NaNb3(TeO4)4 crystallizes in the monoclinic P2_1/m space group. Na(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(4), two equivalent O(7), and two equivalent O(9) atoms. Both Na(1)-O(2) bond lengths are 2.93 Å. Both Na(1)-O(4) bond lengths are 2.67 Å. Both Na(1)-O(7) bond lengths are 2.52 Å. Both Na(1)-O(9) bond lengths are 2.57 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(8), and one O(9) atom to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 15-36°. The Nb(1)-O(1) bond length is 1.98 Å. The Nb(1)-O(2) bond length is 2.04 Å. The Nb(1)-O(3) bond length is 2.06 Å. The Nb(1)-O(5) bond length is 1.99 Å. The Nb(1)-O(8) bond length is 1.88 Å. The Nb(1)-O(9) bond length is 2.20 Å. In the second Nb site, Nb(2) is bonded to two equivalent O(10), two equivalent O(11), and two equivalent O(8) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 15-32°. Both Nb(2)-O(10) bond lengths are 2.03 Å. Both Nb(2)-O(11) bond lengths are 1.97 Å. Both Nb(2)-O(8) bond lengths are 2.02 Å. There are four inequivalent Te sites. In the first Te site, Te(1) is bonded in a 3-coordinate geometry to one O(6) and two equivalent O(10) atoms. The Te(1)-O(6) bond length is 1.84 Å. Both Te(1)-O(10) bond lengths are 1.94 Å. In the second Te site, Te(2) is bonded in a distorted rectangular see-saw-like geometry to one O(6), one O(7), and two equivalent O(3) atoms. The Te(2)-O(6) bond length is 2.21 Å. The Te(2)-O(7) bond length is 2.04 Å. Both Te(2)-O(3) bond lengths are 1.93 Å. In the third Te site, Te(3) is bonded in a distorted rectangular see-saw-like geometry to one O(4), one O(7), and two equivalent O(9) atoms. The Te(3)-O(4) bond length is 2.48 Å. The Te(3)-O(7) bond length is 2.06 Å. Both Te(3)-O(9) bond lengths are 1.91 Å. In the fourth Te site, Te(4) is bonded in a 3-coordinate geometry to one O(4) and two equivalent O(2) atoms. The Te(4)-O(4) bond length is 1.87 Å. Both Te(4)-O(2) bond lengths are 1.95 Å. There are eleven inequivalent O sites. In the first O site, O(10) is bonded in a bent 150 degrees geometry to one Nb(2) and one Te(1) atom. In the second O site, O(11) is bonded in a bent 150 degrees geometry to two equivalent Nb(2) atoms. In the third O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Nb(1) atoms. In the fourth O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Nb(1), and one Te(4) atom. In the fifth O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Nb(1) and one Te(2) atom. In the sixth O site, O(4) is bonded to two equivalent Na(1), one Te(3), and one Te(4) atom to form a mixture of distorted edge and corner-sharing ONa2Te2 tetrahedra. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to two equivalent Nb(1) atoms. In the eighth O site, O(6) is bonded in a bent 150 degrees geometry to one Te(1) and one Te(2) atom. In the ninth O site, O(7) is bonded to two equivalent Na(1), one Te(2), and one Te(3) atom to form a mixture of distorted edge and corner-sharing ONa2Te2 tetrahedra. In the tenth O site, O(8) is bonded in a linear geometry to one Nb(1) and one Nb(2) atom. In the eleventh O site, O(9) is bonded in a distorted trigonal non-coplanar geometry to one Na(1), one Nb(1), and one Te(3) atom.