Pr9K(SiO4)6O2 crystallizes in the trigonal P3 space group. K(1) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(4), and three equivalent O(7) atoms. There are five inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 9-coordinate geometry to three equivalent O(2), three equivalent O(3), and three equivalent O(8) atoms. In the second Pr site, Pr(2) is bonded in a 9-coordinate geometry to three equivalent O(2), three equivalent O(3), and three equivalent O(9) atoms. In the third Pr site, Pr(3) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(10), and three equivalent O(4) atoms. In the fourth Pr site, Pr(4) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(3), one O(5), one O(7), one O(8), and one O(9) atom. In the fifth Pr site, Pr(5) is bonded in a 7-coordinate geometry to one O(10), one O(2), one O(4), one O(6), one O(7), one O(8), and one O(9) atom. 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(10), one O(3), 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(8), and one O(9) atom. There are ten inequivalent O sites. In the first O site, O(8) is bonded in a 1-coordinate geometry to one Pr(1), one Pr(4), one Pr(5), and one Si(2) atom. In the second O site, O(9) is bonded in a 1-coordinate geometry to one Pr(2), one Pr(4), one Pr(5), and one Si(2) atom. In the third O site, O(10) is bonded in a 1-coordinate geometry to one Pr(3), one Pr(4), one Pr(5), and one Si(1) atom. In the fourth O site, O(1) is bonded in a 4-coordinate geometry to one K(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 Pr(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 K(1), one Pr(3), one Pr(5), and one Si(2) atom. In the eighth O site, O(5) is bonded in a trigonal planar geometry to three equivalent Pr(4) atoms. In the ninth O site, O(6) is bonded in a trigonal planar geometry to three equivalent Pr(5) atoms. In the tenth O site, O(7) is bonded in a 1-coordinate geometry to one K(1), one Pr(4), one Pr(5), and one Si(1) atom.
Pr9K(SiO4)6O2 crystallizes in the trigonal P3 space group. K(1) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(4), and three equivalent O(7) atoms. All K(1)-O(1) bond lengths are 2.71 Å. All K(1)-O(4) bond lengths are 2.65 Å. All K(1)-O(7) bond lengths are 3.02 Å. There are five inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 9-coordinate geometry to three equivalent O(2), three equivalent O(3), and three equivalent O(8) atoms. All Pr(1)-O(2) bond lengths are 2.52 Å. All Pr(1)-O(3) bond lengths are 2.46 Å. All Pr(1)-O(8) bond lengths are 2.79 Å. In the second Pr site, Pr(2) is bonded in a 9-coordinate geometry to three equivalent O(2), three equivalent O(3), and three equivalent O(9) atoms. All Pr(2)-O(2) bond lengths are 2.52 Å. All Pr(2)-O(3) bond lengths are 2.46 Å. All Pr(2)-O(9) bond lengths are 2.85 Å. In the third Pr site, Pr(3) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(10), and three equivalent O(4) atoms. All Pr(3)-O(1) bond lengths are 2.50 Å. All Pr(3)-O(10) bond lengths are 2.91 Å. All Pr(3)-O(4) bond lengths are 2.46 Å. In the fourth Pr site, Pr(4) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(3), one O(5), one O(7), one O(8), and one O(9) atom. The Pr(4)-O(1) bond length is 2.46 Å. The Pr(4)-O(10) bond length is 2.57 Å. The Pr(4)-O(3) bond length is 2.76 Å. The Pr(4)-O(5) bond length is 2.30 Å. The Pr(4)-O(7) bond length is 2.54 Å. The Pr(4)-O(8) bond length is 2.49 Å. The Pr(4)-O(9) bond length is 2.47 Å. In the fifth Pr site, Pr(5) is bonded in a 7-coordinate geometry to one O(10), one O(2), one O(4), one O(6), one O(7), one O(8), and one O(9) atom. The Pr(5)-O(10) bond length is 2.43 Å. The Pr(5)-O(2) bond length is 2.51 Å. The Pr(5)-O(4) bond length is 2.64 Å. The Pr(5)-O(6) bond length is 2.33 Å. The Pr(5)-O(7) bond length is 2.44 Å. The Pr(5)-O(8) bond length is 2.55 Å. The Pr(5)-O(9) bond length is 2.60 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(10), one O(3), and one O(7) atom. The Si(1)-O(1) bond length is 1.63 Å. The Si(1)-O(10) bond length is 1.65 Å. The Si(1)-O(3) bond length is 1.66 Å. The Si(1)-O(7) bond length is 1.65 Å. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(2), one O(4), one O(8), and one O(9) atom. The Si(2)-O(2) bond length is 1.66 Å. The Si(2)-O(4) bond length is 1.61 Å. The Si(2)-O(8) bond length is 1.66 Å. The Si(2)-O(9) bond length is 1.66 Å. There are ten inequivalent O sites. In the first O site, O(8) is bonded in a 1-coordinate geometry to one Pr(1), one Pr(4), one Pr(5), and one Si(2) atom. In the second O site, O(9) is bonded in a 1-coordinate geometry to one Pr(2), one Pr(4), one Pr(5), and one Si(2) atom. In the third O site, O(10) is bonded in a 1-coordinate geometry to one Pr(3), one Pr(4), one Pr(5), and one Si(1) atom. In the fourth O site, O(1) is bonded in a 4-coordinate geometry to one K(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 Pr(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 K(1), one Pr(3), one Pr(5), and one Si(2) atom. In the eighth O site, O(5) is bonded in a trigonal planar geometry to three equivalent Pr(4) atoms. In the ninth O site, O(6) is bonded in a trigonal planar geometry to three equivalent Pr(5) atoms. In the tenth O site, O(7) is bonded in a 1-coordinate geometry to one K(1), one Pr(4), one Pr(5), and one Si(1) atom.