CaNaAlSi2O7 crystallizes in the tetragonal P-42_1m space group. Na(1) is bonded in a 8-coordinate geometry to one O(6), three equivalent O(4), and four equivalent O(5) atoms. Ca(1) is bonded in a 8-coordinate geometry to one O(1), three equivalent O(3), and four equivalent O(2) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent O(2) atoms to form AlO4 tetrahedra that share corners with four equivalent Si(2)O4 tetrahedra. In the second Al site, Al(2) is bonded to four equivalent O(5) atoms to form AlO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(3), one O(6), and two equivalent O(5) atoms to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with two equivalent Al(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(4), and two equivalent O(2) 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(6) is bonded in a distorted trigonal pyramidal geometry to two equivalent Na(1) and two equivalent Si(1) atoms. In the second O site, O(1) is bonded in a distorted trigonal pyramidal geometry to two equivalent Ca(1) and two equivalent Si(2) atoms. In the third O site, O(2) is bonded in a distorted see-saw-like geometry to two equivalent Ca(1), one Al(1), and one Si(2) atom. In the fourth O site, O(3) is bonded in a 1-coordinate geometry to three equivalent Ca(1) and one Si(1) atom. In the fifth O site, O(4) is bonded in a distorted single-bond geometry to three equivalent Na(1) and one Si(2) atom. In the sixth O site, O(5) is bonded in a distorted see-saw-like geometry to two equivalent Na(1), one Al(2), and one Si(1) atom.
CaNaAlSi2O7 crystallizes in the tetragonal P-42_1m space group. Na(1) is bonded in a 8-coordinate geometry to one O(6), three equivalent O(4), and four equivalent O(5) atoms. The Na(1)-O(6) bond length is 2.18 Å. There are two shorter (2.61 Å) and one longer (2.65 Å) Na(1)-O(4) bond length. There are two shorter (2.31 Å) and two longer (2.59 Å) Na(1)-O(5) bond lengths. Ca(1) is bonded in a 8-coordinate geometry to one O(1), three equivalent O(3), and four equivalent O(2) atoms. The Ca(1)-O(1) bond length is 2.26 Å. There are two shorter (2.48 Å) and one longer (2.86 Å) Ca(1)-O(3) bond length. There are two shorter (2.31 Å) and two longer (2.52 Å) Ca(1)-O(2) bond lengths. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent O(2) atoms to form AlO4 tetrahedra that share corners with four equivalent Si(2)O4 tetrahedra. All Al(1)-O(2) bond lengths are 1.80 Å. In the second Al site, Al(2) is bonded to four equivalent O(5) atoms to form AlO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra. All Al(2)-O(5) bond lengths are 1.80 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(3), one O(6), and two equivalent O(5) atoms to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with two equivalent Al(2)O4 tetrahedra. The Si(1)-O(3) bond length is 1.63 Å. The Si(1)-O(6) bond length is 1.66 Å. Both Si(1)-O(5) bond lengths are 1.65 Å. In the second Si site, Si(2) is bonded to one O(1), one O(4), and two equivalent O(2) 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(1) bond length is 1.69 Å. The Si(2)-O(4) bond length is 1.55 Å. Both Si(2)-O(2) bond lengths are 1.70 Å. There are six inequivalent O sites. In the first O site, O(6) is bonded in a distorted trigonal pyramidal geometry to two equivalent Na(1) and two equivalent Si(1) atoms. In the second O site, O(1) is bonded in a distorted trigonal pyramidal geometry to two equivalent Ca(1) and two equivalent Si(2) atoms. In the third O site, O(2) is bonded in a distorted see-saw-like geometry to two equivalent Ca(1), one Al(1), and one Si(2) atom. In the fourth O site, O(3) is bonded in a 1-coordinate geometry to three equivalent Ca(1) and one Si(1) atom. In the fifth O site, O(4) is bonded in a distorted single-bond geometry to three equivalent Na(1) and one Si(2) atom. In the sixth O site, O(5) is bonded in a distorted see-saw-like geometry to two equivalent Na(1), one Al(2), and one Si(1) atom.