Na(SiO4)2 crystallizes in the orthorhombic Pbcn space group. Na(1) is bonded in a 6-coordinate geometry to two equivalent O(5) and four equivalent O(4) atoms. Si(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form corner-sharing SiO4 tetrahedra. There are five inequivalent O sites. In the first O site, O(4) is bonded in a distorted T-shaped geometry to two equivalent Na(1) and one O(3) atom. In the second O site, O(5) is bonded in a linear geometry to two equivalent Na(1) atoms. In the third O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fifth O site, O(3) is bonded in a distorted single-bond geometry to one Si(1) and one O(4) atom.
Na(SiO4)2 crystallizes in the orthorhombic Pbcn space group. Na(1) is bonded in a 6-coordinate geometry to two equivalent O(5) and four equivalent O(4) atoms. Both Na(1)-O(5) bond lengths are 2.47 Å. There are two shorter (2.57 Å) and two longer (2.74 Å) Na(1)-O(4) bond lengths. Si(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form corner-sharing SiO4 tetrahedra. The Si(1)-O(1) bond length is 1.62 Å. The Si(1)-O(3) bond length is 1.68 Å. There is one shorter (1.61 Å) and one longer (1.62 Å) Si(1)-O(2) bond length. There are five inequivalent O sites. In the first O site, O(4) is bonded in a distorted T-shaped geometry to two equivalent Na(1) and one O(3) atom. The O(4)-O(3) bond length is 1.39 Å. In the second O site, O(5) is bonded in a linear geometry to two equivalent Na(1) atoms. In the third O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fifth O site, O(3) is bonded in a distorted single-bond geometry to one Si(1) and one O(4) atom.