CaNaAlSi2O7 crystallizes in the orthorhombic P2_12_12_1 space group. Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(6), and two equivalent O(4) atoms. Ca(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(5), one O(6), and one O(7) atom. Al(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form AlO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra and corners with two equivalent Al(1)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with two equivalent Al(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted tetrahedral geometry to one Na(1), one Ca(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Ca(1), one Al(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Na(1), one Al(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted see-saw-like geometry to two equivalent Na(1), one Al(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Ca(1), one Al(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Na(1), one Ca(1), and one Si(1) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Ca(1) and one Si(2) atom.
CaNaAlSi2O7 crystallizes in the orthorhombic P2_12_12_1 space group. Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(6), and two equivalent O(4) atoms. The Na(1)-O(1) bond length is 2.31 Å. The Na(1)-O(2) bond length is 2.64 Å. The Na(1)-O(3) bond length is 2.37 Å. The Na(1)-O(6) bond length is 2.18 Å. There is one shorter (2.36 Å) and one longer (2.57 Å) Na(1)-O(4) bond length. Ca(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(5), one O(6), and one O(7) atom. The Ca(1)-O(1) bond length is 2.39 Å. The Ca(1)-O(2) bond length is 2.52 Å. The Ca(1)-O(5) bond length is 2.64 Å. The Ca(1)-O(6) bond length is 2.25 Å. The Ca(1)-O(7) bond length is 2.16 Å. Al(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form AlO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. The Al(1)-O(2) bond length is 1.78 Å. The Al(1)-O(3) bond length is 1.76 Å. The Al(1)-O(4) bond length is 1.76 Å. The Al(1)-O(5) bond length is 1.77 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra and corners with two equivalent Al(1)O4 tetrahedra. The Si(1)-O(1) bond length is 1.68 Å. The Si(1)-O(2) bond length is 1.67 Å. The Si(1)-O(5) bond length is 1.64 Å. The Si(1)-O(6) bond length is 1.59 Å. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with two equivalent Al(1)O4 tetrahedra. The Si(2)-O(1) bond length is 1.75 Å. The Si(2)-O(3) bond length is 1.63 Å. The Si(2)-O(4) bond length is 1.65 Å. The Si(2)-O(7) bond length is 1.58 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted tetrahedral geometry to one Na(1), one Ca(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Ca(1), one Al(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Na(1), one Al(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted see-saw-like geometry to two equivalent Na(1), one Al(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Ca(1), one Al(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Na(1), one Ca(1), and one Si(1) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Ca(1) and one Si(2) atom.