NaNb2Bi2O9 crystallizes in the orthorhombic Cmc2_1 space group. Na(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(5) atoms. Nb(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(5) atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 21-33°. Bi(1) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(4) atoms. There are five inequivalent O sites. In the first O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(1) and two equivalent Nb(1) atoms. In the second O site, O(1) is bonded to two equivalent Na(1) and two equivalent Nb(1) atoms to form distorted corner-sharing ONa2Nb2 tetrahedra. In the third O site, O(2) is bonded in a distorted trigonal planar geometry to one Nb(1) and two equivalent Bi(1) atoms. In the fourth O site, O(3) is bonded in a 2-coordinate geometry to one Na(1) and two equivalent Nb(1) atoms. In the fifth O site, O(4) is bonded to four equivalent Bi(1) atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra.
NaNb2Bi2O9 crystallizes in the orthorhombic Cmc2_1 space group. Na(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(5) atoms. There is one shorter (2.44 Å) and one longer (2.47 Å) Na(1)-O(1) bond length. Both Na(1)-O(3) bond lengths are 2.82 Å. There are two shorter (2.48 Å) and two longer (2.55 Å) Na(1)-O(5) bond lengths. Nb(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(5) atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 21-33°. The Nb(1)-O(1) bond length is 2.01 Å. The Nb(1)-O(2) bond length is 2.01 Å. There is one shorter (1.90 Å) and one longer (2.18 Å) Nb(1)-O(3) bond length. There is one shorter (1.88 Å) and one longer (2.24 Å) Nb(1)-O(5) bond length. Bi(1) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(4) atoms. There is one shorter (2.32 Å) and one longer (2.36 Å) Bi(1)-O(2) bond length. There are a spread of Bi(1)-O(4) bond distances ranging from 2.22-2.71 Å. There are five inequivalent O sites. In the first O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(1) and two equivalent Nb(1) atoms. In the second O site, O(1) is bonded to two equivalent Na(1) and two equivalent Nb(1) atoms to form distorted corner-sharing ONa2Nb2 tetrahedra. In the third O site, O(2) is bonded in a distorted trigonal planar geometry to one Nb(1) and two equivalent Bi(1) atoms. In the fourth O site, O(3) is bonded in a 2-coordinate geometry to one Na(1) and two equivalent Nb(1) atoms. In the fifth O site, O(4) is bonded to four equivalent Bi(1) atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra.