Na2SiO3 crystallizes in the orthorhombic Cmc2_1 space group. Na(1) is bonded to one O(1) and four equivalent O(2) atoms to form distorted NaO5 trigonal bipyramids that share corners with four equivalent Si(1)O4 tetrahedra, corners with five equivalent Na(1)O5 trigonal bipyramids,  an edgeedge with one Si(1)O4 tetrahedra, and edges with four equivalent Na(1)O5 trigonal bipyramids. Si(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with eight equivalent Na(1)O5 trigonal bipyramids, and edges with two equivalent Na(1)O5 trigonal bipyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(1) and two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a 5-coordinate geometry to four equivalent Na(1) and one Si(1) atom.
Na2SiO3 crystallizes in the orthorhombic Cmc2_1 space group. Na(1) is bonded to one O(1) and four equivalent O(2) atoms to form distorted NaO5 trigonal bipyramids that share corners with four equivalent Si(1)O4 tetrahedra, corners with five equivalent Na(1)O5 trigonal bipyramids,  an edgeedge with one Si(1)O4 tetrahedra, and edges with four equivalent Na(1)O5 trigonal bipyramids. The Na(1)-O(1) bond length is 2.38 Å. There are a spread of Na(1)-O(2) bond distances ranging from 2.28-2.52 Å. Si(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with eight equivalent Na(1)O5 trigonal bipyramids, and edges with two equivalent Na(1)O5 trigonal bipyramids. There is one shorter (1.67 Å) and one longer (1.68 Å) Si(1)-O(1) bond length. Both Si(1)-O(2) bond lengths are 1.60 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(1) and two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a 5-coordinate geometry to four equivalent Na(1) and one Si(1) atom.