La3Si2O8Cl crystallizes in the monoclinic C2/c space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 9-coordinate geometry to two equivalent O(1), two equivalent O(4), four equivalent O(2), and one Cl(1) atom. In the second La site, La(2) is bonded in a 9-coordinate geometry to one O(2), two equivalent O(1), two equivalent O(4), three equivalent O(3), and one Cl(1) atom. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one La(1), two equivalent La(2), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one La(2), two equivalent La(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to three equivalent La(2) and one Si(1) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to one La(1), two equivalent La(2), and one Si(1) atom. Cl(1) is bonded in a distorted T-shaped geometry to one La(1) and two equivalent La(2) atoms.
La3Si2O8Cl crystallizes in the monoclinic C2/c space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 9-coordinate geometry to two equivalent O(1), two equivalent O(4), four equivalent O(2), and one Cl(1) atom. Both La(1)-O(1) bond lengths are 2.66 Å. Both La(1)-O(4) bond lengths are 2.61 Å. There are two shorter (2.64 Å) and two longer (2.70 Å) La(1)-O(2) bond lengths. The La(1)-Cl(1) bond length is 2.99 Å. In the second La site, La(2) is bonded in a 9-coordinate geometry to one O(2), two equivalent O(1), two equivalent O(4), three equivalent O(3), and one Cl(1) atom. The La(2)-O(2) bond length is 2.57 Å. There is one shorter (2.48 Å) and one longer (2.92 Å) La(2)-O(1) bond length. There is one shorter (2.49 Å) and one longer (2.81 Å) La(2)-O(4) bond length. There are a spread of La(2)-O(3) bond distances ranging from 2.48-2.66 Å. The La(2)-Cl(1) bond length is 2.94 Å. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Si(1)-O(1) bond length is 1.63 Å. The Si(1)-O(2) bond length is 1.66 Å. The Si(1)-O(3) bond length is 1.66 Å. The Si(1)-O(4) bond length is 1.64 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one La(1), two equivalent La(2), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one La(2), two equivalent La(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to three equivalent La(2) and one Si(1) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to one La(1), two equivalent La(2), and one Si(1) atom. Cl(1) is bonded in a distorted T-shaped geometry to one La(1) and two equivalent La(2) atoms.