NaPO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted see-saw-like geometry to one O(1), one O(2), and two equivalent O(4) atoms. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(2), one O(8), and two equivalent O(5) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form corner-sharing PO4 tetrahedra. In the second P site, P(2) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form corner-sharing PO4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Na(2) and one P(1) atom. In the second O site, O(6) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the third O site, O(7) is bonded in a single-bond geometry to one O(8) atom. In the fourth O site, O(8) is bonded in an L-shaped geometry to one Na(2) and one O(7) atom. In the fifth O site, O(1) is bonded in a bent 120 degrees geometry to one Na(1) and one P(2) atom. In the sixth O site, O(2) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one P(2) atom. In the seventh O site, O(3) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the eighth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Na(1) and one P(1) atom.
NaPO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted see-saw-like geometry to one O(1), one O(2), and two equivalent O(4) atoms. The Na(1)-O(1) bond length is 2.30 Å. The Na(1)-O(2) bond length is 2.38 Å. There is one shorter (2.35 Å) and one longer (2.38 Å) Na(1)-O(4) bond length. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(2), one O(8), and two equivalent O(5) atoms. The Na(2)-O(2) bond length is 2.26 Å. The Na(2)-O(8) bond length is 2.84 Å. There is one shorter (2.26 Å) and one longer (2.27 Å) Na(2)-O(5) bond length. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form corner-sharing PO4 tetrahedra. The P(1)-O(3) bond length is 1.62 Å. The P(1)-O(4) bond length is 1.50 Å. The P(1)-O(5) bond length is 1.50 Å. The P(1)-O(6) bond length is 1.63 Å. In the second P site, P(2) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form corner-sharing PO4 tetrahedra. The P(2)-O(1) bond length is 1.49 Å. The P(2)-O(2) bond length is 1.51 Å. The P(2)-O(3) bond length is 1.63 Å. The P(2)-O(6) bond length is 1.63 Å. There are eight inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Na(2) and one P(1) atom. In the second O site, O(6) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the third O site, O(7) is bonded in a single-bond geometry to one O(8) atom. The O(7)-O(8) bond length is 1.23 Å. In the fourth O site, O(8) is bonded in an L-shaped geometry to one Na(2) and one O(7) atom. In the fifth O site, O(1) is bonded in a bent 120 degrees geometry to one Na(1) and one P(2) atom. In the sixth O site, O(2) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one P(2) atom. In the seventh O site, O(3) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the eighth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Na(1) and one P(1) atom.