Ca2La3Si3O13 crystallizes in the hexagonal P6_3/m space group. Ca(1) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(2), and three equivalent O(3) atoms. La(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(4), and four equivalent O(2) atoms. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(3), and two equivalent O(2) atoms. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one La(1), and one Si(1) atom. In the second O site, O(4) is bonded in a trigonal planar geometry to three equivalent La(1) atoms. In the third O site, O(1) is bonded to two equivalent Ca(1), one La(1), and one Si(1) atom to form distorted edge-sharing OCa2LaSi tetrahedra. In the fourth O site, O(2) is bonded in a 1-coordinate geometry to one Ca(1), two equivalent La(1), and one Si(1) atom.
Ca2La3Si3O13 crystallizes in the hexagonal P6_3/m space group. Ca(1) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(2), and three equivalent O(3) atoms. All Ca(1)-O(1) bond lengths are 2.52 Å. All Ca(1)-O(2) bond lengths are 2.92 Å. All Ca(1)-O(3) bond lengths are 2.45 Å. La(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(4), and four equivalent O(2) atoms. The La(1)-O(1) bond length is 2.47 Å. The La(1)-O(3) bond length is 2.76 Å. The La(1)-O(4) bond length is 2.40 Å. There are two shorter (2.41 Å) and two longer (2.58 Å) La(1)-O(2) bond lengths. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(3), and two equivalent O(2) atoms. The Si(1)-O(1) bond length is 1.64 Å. The Si(1)-O(3) bond length is 1.63 Å. Both Si(1)-O(2) bond lengths are 1.66 Å. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one La(1), and one Si(1) atom. In the second O site, O(4) is bonded in a trigonal planar geometry to three equivalent La(1) atoms. In the third O site, O(1) is bonded to two equivalent Ca(1), one La(1), and one Si(1) atom to form distorted edge-sharing OCa2LaSi tetrahedra. In the fourth O site, O(2) is bonded in a 1-coordinate geometry to one Ca(1), two equivalent La(1), and one Si(1) atom.