Na2B4O17 crystallizes in the monoclinic C2/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted hexagonal bipyramidal geometry to two equivalent O(5), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. In the second Na site, Na(2) is bonded in a distorted see-saw-like geometry to two equivalent O(4) and two equivalent O(6) atoms. There are two inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(2), one O(3), and one O(5) atom. There are nine inequivalent O sites. In the first O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Na(2) and one O(7) atom. In the second O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Na(1) and one B(2) atom. In the third O site, O(6) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), and one O(9) atom. In the fourth O site, O(7) is bonded in a water-like geometry to one Na(1) and one O(4) atom. In the fifth O site, O(8) is bonded in an L-shaped geometry to one Na(1) and one O(9) atom. In the sixth O site, O(9) is bonded in a bent 120 degrees geometry to one O(6) and one O(8) atom. In the seventh O site, O(1) is bonded in an L-shaped geometry to two equivalent B(1) atoms. In the eighth O site, O(2) is bonded in a water-like geometry to one B(1) and one B(2) atom. In the ninth O site, O(3) is bonded in a bent 120 degrees geometry to one B(1) and one B(2) atom.
Na2B4O17 crystallizes in the monoclinic C2/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted hexagonal bipyramidal geometry to two equivalent O(5), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. Both Na(1)-O(5) bond lengths are 2.35 Å. Both Na(1)-O(6) bond lengths are 2.63 Å. Both Na(1)-O(7) bond lengths are 2.88 Å. Both Na(1)-O(8) bond lengths are 2.57 Å. In the second Na site, Na(2) is bonded in a distorted see-saw-like geometry to two equivalent O(4) and two equivalent O(6) atoms. Both Na(2)-O(4) bond lengths are 2.88 Å. Both Na(2)-O(6) bond lengths are 2.30 Å. There are two inequivalent B sites. In the first B site, 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 1.42 Å. The B(1)-O(2) bond length is 1.39 Å. The B(1)-O(3) bond length is 1.38 Å. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(2), one O(3), and one O(5) atom. The B(2)-O(2) bond length is 1.46 Å. The B(2)-O(3) bond length is 1.45 Å. The B(2)-O(5) bond length is 1.32 Å. There are nine inequivalent O sites. In the first O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Na(2) and one O(7) atom. The O(4)-O(7) bond length is 1.23 Å. In the second O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Na(1) and one B(2) atom. In the third O site, O(6) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), and one O(9) atom. The O(6)-O(9) bond length is 1.35 Å. In the fourth O site, O(7) is bonded in a water-like geometry to one Na(1) and one O(4) atom. In the fifth O site, O(8) is bonded in an L-shaped geometry to one Na(1) and one O(9) atom. The O(8)-O(9) bond length is 1.28 Å. In the sixth O site, O(9) is bonded in a bent 120 degrees geometry to one O(6) and one O(8) atom. In the seventh O site, O(1) is bonded in an L-shaped geometry to two equivalent B(1) atoms. In the eighth O site, O(2) is bonded in a water-like geometry to one B(1) and one B(2) atom. In the ninth O site, O(3) is bonded in a bent 120 degrees geometry to one B(1) and one B(2) atom.