Na3CoBSiO7 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(6), and two equivalent O(4) atoms. Co(1) is bonded to one O(2), one O(3), one O(5), one O(6), and two equivalent O(4) atoms to form CoO6 octahedra that share corners with four equivalent Si(1)O4 tetrahedra. B(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. Si(1) is bonded to one O(5), one O(6), and two equivalent O(4) atoms to form SiO4 tetrahedra that share corners with four equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-47°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Na(1), two equivalent Na(2), and one B(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(2), one Co(1), and one B(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Na(2), one Co(1), and one B(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(2), one Co(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Na(2), one Co(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to two equivalent Na(2), one Co(1), and one Si(1) atom.
Na3CoBSiO7 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms. The Na(1)-O(2) bond length is 2.38 Å. The Na(1)-O(3) bond length is 2.87 Å. There is one shorter (2.42 Å) and one longer (2.78 Å) Na(1)-O(1) bond length. Both Na(1)-O(4) bond lengths are 2.45 Å. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(6), and two equivalent O(4) atoms. The Na(2)-O(1) bond length is 2.26 Å. The Na(2)-O(2) bond length is 2.50 Å. The Na(2)-O(3) bond length is 2.31 Å. The Na(2)-O(5) bond length is 2.61 Å. The Na(2)-O(6) bond length is 2.28 Å. There is one shorter (2.50 Å) and one longer (2.82 Å) Na(2)-O(4) bond length. Co(1) is bonded to one O(2), one O(3), one O(5), one O(6), and two equivalent O(4) atoms to form CoO6 octahedra that share corners with four equivalent Si(1)O4 tetrahedra. The Co(1)-O(2) bond length is 1.94 Å. The Co(1)-O(3) bond length is 1.92 Å. The Co(1)-O(5) bond length is 1.95 Å. The Co(1)-O(6) bond length is 1.91 Å. Both Co(1)-O(4) bond lengths are 1.91 Å. B(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. The B(1)-O(1) bond length is 1.33 Å. The B(1)-O(2) bond length is 1.39 Å. The B(1)-O(3) bond length is 1.40 Å. Si(1) is bonded to one O(5), one O(6), and two equivalent O(4) atoms to form SiO4 tetrahedra that share corners with four equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-47°. The Si(1)-O(5) bond length is 1.65 Å. The Si(1)-O(6) bond length is 1.62 Å. Both Si(1)-O(4) bond lengths are 1.66 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Na(1), two equivalent Na(2), and one B(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(2), one Co(1), and one B(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Na(2), one Co(1), and one B(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(2), one Co(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Na(2), one Co(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to two equivalent Na(2), one Co(1), and one Si(1) atom.