CaNaAlSi2O7 crystallizes in the orthorhombic Cmm2 space group. Na(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms. Ca(1) is bonded in a 8-coordinate geometry to one O(2), one O(4), two equivalent O(1), two equivalent O(5), and two equivalent O(6) atoms. Al(1) is bonded to two equivalent O(5) and two equivalent O(6) atoms 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(4), and two equivalent O(6) atoms to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with two equivalent Al(1)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(2), one O(3), and two equivalent O(5) atoms to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra and corners with two equivalent Al(1)O4 tetrahedra. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), two equivalent Ca(1), and one Si(1) atom to form distorted ONaCa2Si tetrahedra that share  a cornercorner with one O(4)Ca2Si2 tetrahedra,  an edgeedge with one O(4)Ca2Si2 tetrahedra, and  an edgeedge with one O(1)NaCa2Si tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Ca(1), and one Si(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Na(1) and two equivalent Si(2) atoms. In the fourth O site, O(4) is bonded to two equivalent Ca(1) and two equivalent Si(1) atoms to form a mixture of distorted corner and edge-sharing OCa2Si2 tetrahedra. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Na(1), one Ca(1), one Al(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Na(1), one Ca(1), one Al(1), and one Si(1) atom.
CaNaAlSi2O7 crystallizes in the orthorhombic Cmm2 space group. Na(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms. The Na(1)-O(1) bond length is 2.58 Å. The Na(1)-O(3) bond length is 2.52 Å. Both Na(1)-O(2) bond lengths are 2.65 Å. Both Na(1)-O(5) bond lengths are 2.85 Å. Both Na(1)-O(6) bond lengths are 2.52 Å. Ca(1) is bonded in a 8-coordinate geometry to one O(2), one O(4), two equivalent O(1), two equivalent O(5), and two equivalent O(6) atoms. The Ca(1)-O(2) bond length is 2.35 Å. The Ca(1)-O(4) bond length is 2.46 Å. Both Ca(1)-O(1) bond lengths are 2.58 Å. Both Ca(1)-O(5) bond lengths are 2.43 Å. Both Ca(1)-O(6) bond lengths are 2.81 Å. Al(1) is bonded to two equivalent O(5) and two equivalent O(6) atoms to form AlO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. Both Al(1)-O(5) bond lengths are 1.78 Å. Both Al(1)-O(6) bond lengths are 1.77 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(4), and two equivalent O(6) atoms 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(1)-O(1) bond length is 1.60 Å. The Si(1)-O(4) bond length is 1.69 Å. Both Si(1)-O(6) bond lengths are 1.65 Å. In the second Si site, Si(2) is bonded to one O(2), one O(3), and two equivalent O(5) atoms 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(2)-O(2) bond length is 1.60 Å. The Si(2)-O(3) bond length is 1.66 Å. Both Si(2)-O(5) bond lengths are 1.66 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), two equivalent Ca(1), and one Si(1) atom to form distorted ONaCa2Si tetrahedra that share  a cornercorner with one O(4)Ca2Si2 tetrahedra,  an edgeedge with one O(4)Ca2Si2 tetrahedra, and  an edgeedge with one O(1)NaCa2Si tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Ca(1), and one Si(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Na(1) and two equivalent Si(2) atoms. In the fourth O site, O(4) is bonded to two equivalent Ca(1) and two equivalent Si(1) atoms to form a mixture of distorted corner and edge-sharing OCa2Si2 tetrahedra. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Na(1), one Ca(1), one Al(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Na(1), one Ca(1), one Al(1), and one Si(1) atom.