Pr3Si2O8Cl crystallizes in the monoclinic C2/c space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 9-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(4), three equivalent O(2), and one Cl(1) atom. In the second Pr site, Pr(2) is bonded in a 9-coordinate geometry to two equivalent O(1), two equivalent O(4), four 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 4-coordinate geometry to one Pr(2), two equivalent Pr(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to three equivalent Pr(1) and one Si(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Pr(1), two equivalent Pr(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Pr(2), two equivalent Pr(1), and one Si(1) atom. Cl(1) is bonded in a distorted T-shaped geometry to one Pr(2) and two equivalent Pr(1) atoms.
Pr3Si2O8Cl crystallizes in the monoclinic C2/c space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 9-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(4), three equivalent O(2), and one Cl(1) atom. The Pr(1)-O(3) bond length is 2.52 Å. There is one shorter (2.47 Å) and one longer (2.70 Å) Pr(1)-O(1) bond length. There is one shorter (2.45 Å) and one longer (2.83 Å) Pr(1)-O(4) bond length. There are a spread of Pr(1)-O(2) bond distances ranging from 2.44-2.60 Å. The Pr(1)-Cl(1) bond length is 2.88 Å. In the second Pr site, Pr(2) is bonded in a 9-coordinate geometry to two equivalent O(1), two equivalent O(4), four equivalent O(3), and one Cl(1) atom. Both Pr(2)-O(1) bond lengths are 2.54 Å. Both Pr(2)-O(4) bond lengths are 2.61 Å. There are two shorter (2.60 Å) and two longer (2.67 Å) Pr(2)-O(3) bond lengths. The Pr(2)-Cl(1) bond length is 2.92 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 1.62 Å. The Si(1)-O(2) bond length is 1.64 Å. The Si(1)-O(3) bond length is 1.64 Å. The Si(1)-O(4) bond length is 1.62 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Pr(2), two equivalent Pr(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to three equivalent Pr(1) and one Si(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Pr(1), two equivalent Pr(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Pr(2), two equivalent Pr(1), and one Si(1) atom. Cl(1) is bonded in a distorted T-shaped geometry to one Pr(2) and two equivalent Pr(1) atoms.