Cs4SiO4 crystallizes in the monoclinic P2_1/c space group. There are four inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 7-coordinate geometry to one O(3), one O(4), two equivalent O(2), and three equivalent O(1) atoms. In the second Cs site, Cs(2) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), and two equivalent O(1) atoms. In the third Cs site, Cs(3) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(3), and two equivalent O(4) atoms. In the fourth Cs site, Cs(4) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(3), and two equivalent O(4) atoms. 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 distorted single-bond geometry to two equivalent Cs(2), three equivalent Cs(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Cs(2), one Cs(3), one Cs(4), two equivalent Cs(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Cs(1), one Cs(2), two equivalent Cs(3), two equivalent Cs(4), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Cs(1), one Cs(2), two equivalent Cs(3), two equivalent Cs(4), and one Si(1) atom.
Cs4SiO4 crystallizes in the monoclinic P2_1/c space group. There are four inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 7-coordinate geometry to one O(3), one O(4), two equivalent O(2), and three equivalent O(1) atoms. The Cs(1)-O(3) bond length is 3.59 Å. The Cs(1)-O(4) bond length is 3.42 Å. There is one shorter (3.10 Å) and one longer (3.27 Å) Cs(1)-O(2) bond length. There are a spread of Cs(1)-O(1) bond distances ranging from 2.89-3.32 Å. In the second Cs site, Cs(2) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), and two equivalent O(1) atoms. The Cs(2)-O(2) bond length is 2.99 Å. The Cs(2)-O(3) bond length is 2.98 Å. The Cs(2)-O(4) bond length is 3.42 Å. There is one shorter (3.01 Å) and one longer (3.04 Å) Cs(2)-O(1) bond length. In the third Cs site, Cs(3) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(3), and two equivalent O(4) atoms. The Cs(3)-O(2) bond length is 2.85 Å. There is one shorter (3.10 Å) and one longer (3.60 Å) Cs(3)-O(3) bond length. There is one shorter (2.87 Å) and one longer (3.13 Å) Cs(3)-O(4) bond length. In the fourth Cs site, Cs(4) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(3), and two equivalent O(4) atoms. The Cs(4)-O(2) bond length is 3.00 Å. There is one shorter (2.95 Å) and one longer (3.29 Å) Cs(4)-O(3) bond length. There is one shorter (2.96 Å) and one longer (3.06 Å) Cs(4)-O(4) bond length. 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 1.65 Å. The Si(1)-O(2) bond length is 1.66 Å. The Si(1)-O(3) bond length is 1.67 Å. The Si(1)-O(4) bond length is 1.66 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Cs(2), three equivalent Cs(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Cs(2), one Cs(3), one Cs(4), two equivalent Cs(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Cs(1), one Cs(2), two equivalent Cs(3), two equivalent Cs(4), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Cs(1), one Cs(2), two equivalent Cs(3), two equivalent Cs(4), and one Si(1) atom.