La3Si2O8Cl crystallizes in the monoclinic Cc space group. There are three inequivalent La sites. In the first La site, La(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(7), one O(8), two equivalent O(6), and one Cl(1) atom. In the second La site, La(2) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(4), one O(6), one O(7), one O(8), two equivalent O(5), and one Cl(1) atom. In the third La site, La(3) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(7), one O(8), two equivalent O(3), two equivalent O(4), and one Cl(1) atom. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a tetrahedral geometry to one O(2), one O(4), one O(6), and one O(7) atom. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(1), one O(3), one O(5), and one O(8) atom. There are eight inequivalent O sites. In the first O site, O(5) is bonded in a 4-coordinate geometry to one La(1), two equivalent La(2), and one Si(2) atom. In the second O site, O(6) is bonded in a 4-coordinate geometry to one La(2), two equivalent La(1), and one Si(1) atom. In the third O site, O(7) is bonded in a 1-coordinate geometry to one La(1), one La(2), one La(3), and one Si(1) atom. In the fourth O site, O(8) is bonded in a 1-coordinate geometry to one La(1), one La(2), one La(3), and one Si(2) atom. In the fifth O site, O(1) is bonded in a 1-coordinate geometry to one La(1), one La(2), one La(3), and one Si(2) atom. In the sixth O site, O(2) is bonded in a 1-coordinate geometry to one La(1), one La(2), one La(3), and one Si(1) atom. In the seventh O site, O(3) is bonded in a distorted single-bond geometry to one La(1), two equivalent La(3), and one Si(2) atom. In the eighth O site, O(4) is bonded in a distorted single-bond geometry to one La(2), two equivalent La(3), and one Si(1) atom. Cl(1) is bonded in a distorted T-shaped geometry to one La(1), one La(2), and one La(3) atom.
La3Si2O8Cl crystallizes in the monoclinic Cc space group. There are three inequivalent La sites. In the first La site, La(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(7), one O(8), two equivalent O(6), and one Cl(1) atom. The La(1)-O(1) bond length is 2.50 Å. The La(1)-O(2) bond length is 2.81 Å. The La(1)-O(3) bond length is 2.58 Å. The La(1)-O(5) bond length is 2.67 Å. The La(1)-O(7) bond length is 2.92 Å. The La(1)-O(8) bond length is 2.48 Å. There is one shorter (2.48 Å) and one longer (2.52 Å) La(1)-O(6) bond length. The La(1)-Cl(1) bond length is 2.94 Å. In the second La site, La(2) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(4), one O(6), one O(7), one O(8), two equivalent O(5), and one Cl(1) atom. The La(2)-O(1) bond length is 2.80 Å. The La(2)-O(2) bond length is 2.49 Å. The La(2)-O(4) bond length is 2.58 Å. The La(2)-O(6) bond length is 2.66 Å. The La(2)-O(7) bond length is 2.48 Å. The La(2)-O(8) bond length is 2.92 Å. There is one shorter (2.48 Å) and one longer (2.52 Å) La(2)-O(5) bond length. The La(2)-Cl(1) bond length is 2.95 Å. In the third La site, La(3) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(7), one O(8), two equivalent O(3), two equivalent O(4), and one Cl(1) atom. The La(3)-O(1) bond length is 2.61 Å. The La(3)-O(2) bond length is 2.61 Å. The La(3)-O(7) bond length is 2.67 Å. The La(3)-O(8) bond length is 2.66 Å. There is one shorter (2.64 Å) and one longer (2.69 Å) La(3)-O(3) bond length. There is one shorter (2.64 Å) and one longer (2.70 Å) La(3)-O(4) bond length. The La(3)-Cl(1) bond length is 3.01 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a tetrahedral geometry to one O(2), one O(4), one O(6), and one O(7) atom. The Si(1)-O(2) bond length is 1.64 Å. The Si(1)-O(4) bond length is 1.66 Å. The Si(1)-O(6) bond length is 1.66 Å. The Si(1)-O(7) bond length is 1.63 Å. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(1), one O(3), one O(5), and one O(8) atom. The Si(2)-O(1) bond length is 1.64 Å. The Si(2)-O(3) bond length is 1.66 Å. The Si(2)-O(5) bond length is 1.66 Å. The Si(2)-O(8) bond length is 1.63 Å. There are eight inequivalent O sites. In the first O site, O(5) is bonded in a 4-coordinate geometry to one La(1), two equivalent La(2), and one Si(2) atom. In the second O site, O(6) is bonded in a 4-coordinate geometry to one La(2), two equivalent La(1), and one Si(1) atom. In the third O site, O(7) is bonded in a 1-coordinate geometry to one La(1), one La(2), one La(3), and one Si(1) atom. In the fourth O site, O(8) is bonded in a 1-coordinate geometry to one La(1), one La(2), one La(3), and one Si(2) atom. In the fifth O site, O(1) is bonded in a 1-coordinate geometry to one La(1), one La(2), one La(3), and one Si(2) atom. In the sixth O site, O(2) is bonded in a 1-coordinate geometry to one La(1), one La(2), one La(3), and one Si(1) atom. In the seventh O site, O(3) is bonded in a distorted single-bond geometry to one La(1), two equivalent La(3), and one Si(2) atom. In the eighth O site, O(4) is bonded in a distorted single-bond geometry to one La(2), two equivalent La(3), and one Si(1) atom. Cl(1) is bonded in a distorted T-shaped geometry to one La(1), one La(2), and one La(3) atom.