K6MgCu(SiO4)2 crystallizes in the triclinic P1 space group. There are six inequivalent K sites. In the first K site, K(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(7) atom. In the second K site, K(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. In the third K site, K(3) is bonded in a 3-coordinate geometry to one O(1), one O(4), one O(7), and one O(8) atom. In the fourth K site, K(4) is bonded in a 4-coordinate geometry to one O(2), one O(3), one O(6), and one O(7) atom. In the fifth K site, K(5) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. In the sixth K site, K(6) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and one O(8) atom. Mg(1) is bonded in a 2-coordinate geometry to one O(5) and one O(8) atom. Cu(1) is bonded in a 3-coordinate geometry to one O(4), one O(6), and one O(7) 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(2), one O(4), and one O(7) atom. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(3), one O(5), one O(6), and one O(8) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(3), one K(5), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(4), one K(5), one K(6), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(4), one K(5), one K(6), and one Si(2) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one K(2), one K(3), one K(5), one K(6), one Cu(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one K(2), one K(5), one K(6), one Mg(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one K(2), one K(4), one K(5), one Cu(1), and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal bipyramidal geometry to one K(1), one K(3), one K(4), one Cu(1), and one Si(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one K(3), one K(6), one Mg(1), and one Si(2) atom.
K6MgCu(SiO4)2 crystallizes in the triclinic P1 space group. There are six inequivalent K sites. In the first K site, K(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(7) atom. The K(1)-O(1) bond length is 2.67 Å. The K(1)-O(2) bond length is 2.98 Å. The K(1)-O(3) bond length is 2.90 Å. The K(1)-O(7) bond length is 2.65 Å. In the second K site, K(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. The K(2)-O(1) bond length is 2.79 Å. The K(2)-O(2) bond length is 3.35 Å. The K(2)-O(3) bond length is 3.21 Å. The K(2)-O(4) bond length is 2.74 Å. The K(2)-O(5) bond length is 2.69 Å. The K(2)-O(6) bond length is 2.83 Å. In the third K site, K(3) is bonded in a 3-coordinate geometry to one O(1), one O(4), one O(7), and one O(8) atom. The K(3)-O(1) bond length is 2.72 Å. The K(3)-O(4) bond length is 3.14 Å. The K(3)-O(7) bond length is 2.68 Å. The K(3)-O(8) bond length is 2.72 Å. In the fourth K site, K(4) is bonded in a 4-coordinate geometry to one O(2), one O(3), one O(6), and one O(7) atom. The K(4)-O(2) bond length is 2.67 Å. The K(4)-O(3) bond length is 2.95 Å. The K(4)-O(6) bond length is 2.88 Å. The K(4)-O(7) bond length is 2.55 Å. In the fifth K site, K(5) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. The K(5)-O(1) bond length is 2.68 Å. The K(5)-O(2) bond length is 2.85 Å. The K(5)-O(3) bond length is 2.98 Å. The K(5)-O(4) bond length is 2.85 Å. The K(5)-O(5) bond length is 2.92 Å. The K(5)-O(6) bond length is 3.16 Å. In the sixth K site, K(6) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and one O(8) atom. The K(6)-O(2) bond length is 3.30 Å. The K(6)-O(3) bond length is 2.86 Å. The K(6)-O(4) bond length is 3.15 Å. The K(6)-O(5) bond length is 2.78 Å. The K(6)-O(8) bond length is 2.67 Å. Mg(1) is bonded in a 2-coordinate geometry to one O(5) and one O(8) atom. The Mg(1)-O(5) bond length is 2.04 Å. The Mg(1)-O(8) bond length is 2.04 Å. Cu(1) is bonded in a 3-coordinate geometry to one O(4), one O(6), and one O(7) atom. The Cu(1)-O(4) bond length is 1.94 Å. The Cu(1)-O(6) bond length is 1.91 Å. The Cu(1)-O(7) bond length is 2.25 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(2), one O(4), and one O(7) 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(4) bond length is 1.71 Å. The Si(1)-O(7) bond length is 1.67 Å. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(3), one O(5), one O(6), and one O(8) atom. The Si(2)-O(3) bond length is 1.62 Å. The Si(2)-O(5) bond length is 1.68 Å. The Si(2)-O(6) bond length is 1.69 Å. The Si(2)-O(8) bond length is 1.68 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(3), one K(5), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(4), one K(5), one K(6), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(4), one K(5), one K(6), and one Si(2) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one K(2), one K(3), one K(5), one K(6), one Cu(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one K(2), one K(5), one K(6), one Mg(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one K(2), one K(4), one K(5), one Cu(1), and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal bipyramidal geometry to one K(1), one K(3), one K(4), one Cu(1), and one Si(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one K(3), one K(6), one Mg(1), and one Si(2) atom.