NaPr9Si6(SO12)2 crystallizes in the trigonal P3 space group. Na(1) is bonded in a 6-coordinate geometry to three equivalent O(2) and three equivalent O(7) atoms. There are five inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 8-coordinate geometry to one S(1), one S(2), one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. In the second Pr site, Pr(2) is bonded in a 8-coordinate geometry to one S(1), one S(2), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom. In the third Pr site, Pr(3) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(6), and three equivalent O(8) atoms. In the fourth Pr site, Pr(4) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(3), and three equivalent O(8) atoms. In the fifth Pr site, Pr(5) is bonded in a 9-coordinate geometry to three equivalent O(2), three equivalent O(4), and three equivalent O(7) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a tetrahedral geometry to one O(1), one O(3), one O(6), and one O(7) atom. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(2), one O(4), one O(5), and one O(8) atom. There are two inequivalent S sites. In the first S site, S(1) is bonded to three equivalent Pr(1) and three equivalent Pr(2) atoms to form face-sharing SPr6 octahedra. In the second S site, S(2) is bonded to three equivalent Pr(1) and three equivalent Pr(2) atoms to form face-sharing SPr6 octahedra. There are eight inequivalent O sites. In the first O site, O(6) is bonded in a 4-coordinate geometry to one Pr(1), one Pr(2), one Pr(3), and one Si(1) atom. In the second O site, O(7) is bonded in a 1-coordinate geometry to one Na(1), one Pr(1), one Pr(5), and one Si(1) atom. In the third O site, O(8) is bonded in a 3-coordinate geometry to one Pr(2), one Pr(3), one Pr(4), and one Si(2) atom. In the fourth O site, O(1) is bonded in a 4-coordinate geometry to one Pr(1), one Pr(3), one Pr(4), and one Si(1) atom. In the fifth O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Pr(2), one Pr(5), and one Si(2) atom. In the sixth O site, O(3) is bonded in a 4-coordinate geometry to one Pr(1), one Pr(2), one Pr(4), and one Si(1) atom. In the seventh O site, O(4) is bonded in a 4-coordinate geometry to one Pr(1), one Pr(2), one Pr(5), and one Si(2) atom. In the eighth O site, O(5) is bonded in a 3-coordinate geometry to one Pr(1), one Pr(2), and one Si(2) atom.
NaPr9Si6(SO12)2 crystallizes in the trigonal P3 space group. Na(1) is bonded in a 6-coordinate geometry to three equivalent O(2) and three equivalent O(7) atoms. All Na(1)-O(2) bond lengths are 2.60 Å. All Na(1)-O(7) bond lengths are 2.52 Å. There are five inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 8-coordinate geometry to one S(1), one S(2), one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. The Pr(1)-S(1) bond length is 2.98 Å. The Pr(1)-S(2) bond length is 3.02 Å. The Pr(1)-O(1) bond length is 2.40 Å. The Pr(1)-O(3) bond length is 2.61 Å. The Pr(1)-O(4) bond length is 2.41 Å. The Pr(1)-O(5) bond length is 2.39 Å. The Pr(1)-O(6) bond length is 2.59 Å. The Pr(1)-O(7) bond length is 2.94 Å. In the second Pr site, Pr(2) is bonded in a 8-coordinate geometry to one S(1), one S(2), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom. The Pr(2)-S(1) bond length is 3.03 Å. The Pr(2)-S(2) bond length is 3.02 Å. The Pr(2)-O(2) bond length is 2.35 Å. The Pr(2)-O(3) bond length is 2.45 Å. The Pr(2)-O(4) bond length is 2.58 Å. The Pr(2)-O(5) bond length is 2.50 Å. The Pr(2)-O(6) bond length is 2.48 Å. The Pr(2)-O(8) bond length is 3.13 Å. In the third Pr site, Pr(3) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(6), and three equivalent O(8) atoms. All Pr(3)-O(1) bond lengths are 2.51 Å. All Pr(3)-O(6) bond lengths are 2.75 Å. All Pr(3)-O(8) bond lengths are 2.43 Å. In the fourth Pr site, Pr(4) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(3), and three equivalent O(8) atoms. All Pr(4)-O(1) bond lengths are 2.51 Å. All Pr(4)-O(3) bond lengths are 2.77 Å. All Pr(4)-O(8) bond lengths are 2.44 Å. In the fifth Pr site, Pr(5) is bonded in a 9-coordinate geometry to three equivalent O(2), three equivalent O(4), and three equivalent O(7) atoms. All Pr(5)-O(2) bond lengths are 2.53 Å. All Pr(5)-O(4) bond lengths are 2.81 Å. All Pr(5)-O(7) bond lengths are 2.45 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a tetrahedral geometry to one O(1), one O(3), one O(6), and one O(7) atom. The Si(1)-O(1) bond length is 1.67 Å. The Si(1)-O(3) 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 1.61 Å. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(2), one O(4), one O(5), and one O(8) atom. The Si(2)-O(2) bond length is 1.64 Å. The Si(2)-O(4) bond length is 1.65 Å. The Si(2)-O(5) bond length is 1.64 Å. The Si(2)-O(8) bond length is 1.65 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded to three equivalent Pr(1) and three equivalent Pr(2) atoms to form face-sharing SPr6 octahedra. In the second S site, S(2) is bonded to three equivalent Pr(1) and three equivalent Pr(2) atoms to form face-sharing SPr6 octahedra. There are eight inequivalent O sites. In the first O site, O(6) is bonded in a 4-coordinate geometry to one Pr(1), one Pr(2), one Pr(3), and one Si(1) atom. In the second O site, O(7) is bonded in a 1-coordinate geometry to one Na(1), one Pr(1), one Pr(5), and one Si(1) atom. In the third O site, O(8) is bonded in a 3-coordinate geometry to one Pr(2), one Pr(3), one Pr(4), and one Si(2) atom. In the fourth O site, O(1) is bonded in a 4-coordinate geometry to one Pr(1), one Pr(3), one Pr(4), and one Si(1) atom. In the fifth O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Pr(2), one Pr(5), and one Si(2) atom. In the sixth O site, O(3) is bonded in a 4-coordinate geometry to one Pr(1), one Pr(2), one Pr(4), and one Si(1) atom. In the seventh O site, O(4) is bonded in a 4-coordinate geometry to one Pr(1), one Pr(2), one Pr(5), and one Si(2) atom. In the eighth O site, O(5) is bonded in a 3-coordinate geometry to one Pr(1), one Pr(2), and one Si(2) atom.