(Na2Ce(Si3O8)2)4O2 crystallizes in the orthorhombic Pmm2 space group. The structure consists of one water atom inside a Na2Ce(Si3O8)2 framework. In the Na2Ce(Si3O8)2 framework, there are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(10), one O(12), two equivalent O(2), and two equivalent O(3) atoms. In the second Na site, Na(2) is bonded to one O(6), two equivalent O(12), and two equivalent O(9) atoms to form distorted NaO5 trigonal bipyramids that share corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, and edges with two equivalent Na(2)O5 trigonal bipyramids. Ce(1) is bonded in a 7-coordinate geometry to one O(7), one O(8), one O(9), two equivalent O(2), and two equivalent O(3) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(10), one O(3), and one O(4) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(11), one O(2), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  a cornercorner with one Na(2)O5 trigonal bipyramid. In the third Si site, Si(3) is bonded to one O(7), one O(8), and two equivalent O(4) atoms to form corner-sharing SiO4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(8), one O(9), and two equivalent O(5) atoms to form SiO4 tetrahedra that share  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent Na(2)O5 trigonal bipyramids. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Ce(1), and one Si(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Ce(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Si(1) and one Si(3) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Na(2) and two equivalent Si(2) atoms. In the seventh O site, O(7) is bonded in a distorted linear geometry to one Ce(1) and one Si(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Ce(1), one Si(3), and one Si(4) atom. In the ninth O site, O(9) is bonded to two equivalent Na(2), one Ce(1), and one Si(4) atom to form distorted edge-sharing ONa2CeSi tetrahedra. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Na(1) and two equivalent Si(1) atoms. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to two equivalent Si(2) atoms. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Na(1) and two equivalent Na(2) atoms.
(Na2Ce(Si3O8)2)4O2 crystallizes in the orthorhombic Pmm2 space group. The structure consists of one water atom inside a Na2Ce(Si3O8)2 framework. In the Na2Ce(Si3O8)2 framework, there are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(10), one O(12), two equivalent O(2), and two equivalent O(3) atoms. The Na(1)-O(10) bond length is 2.81 Å. The Na(1)-O(12) bond length is 2.30 Å. Both Na(1)-O(2) bond lengths are 2.55 Å. Both Na(1)-O(3) bond lengths are 2.45 Å. In the second Na site, Na(2) is bonded to one O(6), two equivalent O(12), and two equivalent O(9) atoms to form distorted NaO5 trigonal bipyramids that share corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, and edges with two equivalent Na(2)O5 trigonal bipyramids. The Na(2)-O(6) bond length is 2.42 Å. Both Na(2)-O(12) bond lengths are 2.73 Å. Both Na(2)-O(9) bond lengths are 2.45 Å. Ce(1) is bonded in a 7-coordinate geometry to one O(7), one O(8), one O(9), two equivalent O(2), and two equivalent O(3) atoms. The Ce(1)-O(7) bond length is 2.18 Å. The Ce(1)-O(8) bond length is 2.76 Å. The Ce(1)-O(9) bond length is 2.50 Å. Both Ce(1)-O(2) bond lengths are 2.37 Å. Both Ce(1)-O(3) bond lengths are 2.21 Å. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(10), one O(3), and one O(4) atom to form corner-sharing SiO4 tetrahedra. The Si(1)-O(1) bond length is 1.63 Å. The Si(1)-O(10) bond length is 1.64 Å. The Si(1)-O(3) bond length is 1.62 Å. The Si(1)-O(4) bond length is 1.64 Å. In the second Si site, Si(2) is bonded to one O(11), one O(2), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  a cornercorner with one Na(2)O5 trigonal bipyramid. The Si(2)-O(11) bond length is 1.63 Å. The Si(2)-O(2) bond length is 1.62 Å. The Si(2)-O(5) bond length is 1.63 Å. The Si(2)-O(6) bond length is 1.65 Å. In the third Si site, Si(3) is bonded to one O(7), one O(8), and two equivalent O(4) atoms to form corner-sharing SiO4 tetrahedra. The Si(3)-O(7) bond length is 1.60 Å. The Si(3)-O(8) bond length is 1.67 Å. Both Si(3)-O(4) bond lengths are 1.64 Å. In the fourth Si site, Si(4) is bonded to one O(8), one O(9), and two equivalent O(5) atoms to form SiO4 tetrahedra that share  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent Na(2)O5 trigonal bipyramids. The Si(4)-O(8) bond length is 1.64 Å. The Si(4)-O(9) bond length is 1.61 Å. Both Si(4)-O(5) bond lengths are 1.63 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Ce(1), and one Si(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Ce(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Si(1) and one Si(3) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Na(2) and two equivalent Si(2) atoms. In the seventh O site, O(7) is bonded in a distorted linear geometry to one Ce(1) and one Si(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Ce(1), one Si(3), and one Si(4) atom. In the ninth O site, O(9) is bonded to two equivalent Na(2), one Ce(1), and one Si(4) atom to form distorted edge-sharing ONa2CeSi tetrahedra. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Na(1) and two equivalent Si(1) atoms. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to two equivalent Si(2) atoms. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Na(1) and two equivalent Na(2) atoms.