Tm2Cu(GeO4)2 crystallizes in the monoclinic Cm space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom. In the second Tm site, Tm(2) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(2), one O(4), one O(5), one O(7), one O(8), and one O(9) atom. Cu(1) is bonded in a 6-coordinate geometry to one O(10), one O(2), one O(4), one O(8), and two equivalent O(1) atoms. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a tetrahedral geometry to one O(6), one O(9), and two equivalent O(2) atoms. In the second Ge site, Ge(2) is bonded to one O(1), one O(10), one O(4), one O(5), and one O(8) atom to form corner-sharing GeO5 trigonal bipyramids. In the third Ge site, Ge(3) is bonded to one O(3), one O(7), and two equivalent O(5) atoms to form corner-sharing GeO4 tetrahedra. There are ten inequivalent O sites. In the first O site, O(9) is bonded in a trigonal planar geometry to two equivalent Tm(2) and one Ge(1) atom. In the second O site, O(10) is bonded to one Tm(1), one Tm(2), one Cu(1), and one Ge(2) atom to form a mixture of distorted edge and corner-sharing OTm2CuGe trigonal pyramids. In the third O site, O(1) is bonded in a 5-coordinate geometry to one Tm(1), one Tm(2), two equivalent Cu(1), and one Ge(2) atom. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Tm(1), one Tm(2), one Cu(1), and one Ge(1) atom. In the fifth O site, O(3) is bonded in a trigonal planar geometry to two equivalent Tm(1) and one Ge(3) atom. In the sixth O site, O(4) is bonded to one Tm(1), one Tm(2), one Cu(1), and one Ge(2) atom to form a mixture of distorted edge and corner-sharing OTm2CuGe trigonal pyramids. In the seventh O site, O(5) is bonded in a 4-coordinate geometry to one Tm(1), one Tm(2), one Ge(2), and one Ge(3) atom. In the eighth O site, O(6) is bonded in a trigonal planar geometry to two equivalent Tm(1) and one Ge(1) atom. In the ninth O site, O(7) is bonded in a trigonal planar geometry to two equivalent Tm(2) and one Ge(3) atom. In the tenth O site, O(8) is bonded to one Tm(1), one Tm(2), one Cu(1), and one Ge(2) atom to form a mixture of edge and corner-sharing OTm2CuGe trigonal pyramids.
Tm2Cu(GeO4)2 crystallizes in the monoclinic Cm space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom. The Tm(1)-O(1) bond length is 2.46 Å. The Tm(1)-O(10) bond length is 2.21 Å. The Tm(1)-O(2) bond length is 2.80 Å. The Tm(1)-O(3) bond length is 2.24 Å. The Tm(1)-O(4) bond length is 2.41 Å. The Tm(1)-O(5) bond length is 2.63 Å. The Tm(1)-O(6) bond length is 2.24 Å. The Tm(1)-O(8) bond length is 2.34 Å. In the second Tm site, Tm(2) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(2), one O(4), one O(5), one O(7), one O(8), and one O(9) atom. The Tm(2)-O(1) bond length is 2.36 Å. The Tm(2)-O(10) bond length is 2.29 Å. The Tm(2)-O(2) bond length is 2.53 Å. The Tm(2)-O(4) bond length is 2.40 Å. The Tm(2)-O(5) bond length is 2.72 Å. The Tm(2)-O(7) bond length is 2.27 Å. The Tm(2)-O(8) bond length is 2.38 Å. The Tm(2)-O(9) bond length is 2.24 Å. Cu(1) is bonded in a 6-coordinate geometry to one O(10), one O(2), one O(4), one O(8), and two equivalent O(1) atoms. The Cu(1)-O(10) bond length is 1.91 Å. The Cu(1)-O(2) bond length is 1.95 Å. The Cu(1)-O(4) bond length is 2.01 Å. The Cu(1)-O(8) bond length is 2.07 Å. There is one shorter (2.44 Å) and one longer (2.63 Å) Cu(1)-O(1) bond length. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a tetrahedral geometry to one O(6), one O(9), and two equivalent O(2) atoms. The Ge(1)-O(6) bond length is 1.79 Å. The Ge(1)-O(9) bond length is 1.79 Å. Both Ge(1)-O(2) bond lengths are 1.79 Å. In the second Ge site, Ge(2) is bonded to one O(1), one O(10), one O(4), one O(5), and one O(8) atom to form corner-sharing GeO5 trigonal bipyramids. The Ge(2)-O(1) bond length is 1.78 Å. The Ge(2)-O(10) bond length is 1.95 Å. The Ge(2)-O(4) bond length is 1.81 Å. The Ge(2)-O(5) bond length is 1.94 Å. The Ge(2)-O(8) bond length is 1.83 Å. In the third Ge site, Ge(3) is bonded to one O(3), one O(7), and two equivalent O(5) atoms to form corner-sharing GeO4 tetrahedra. The Ge(3)-O(3) bond length is 1.77 Å. The Ge(3)-O(7) bond length is 1.77 Å. Both Ge(3)-O(5) bond lengths are 1.80 Å. There are ten inequivalent O sites. In the first O site, O(9) is bonded in a trigonal planar geometry to two equivalent Tm(2) and one Ge(1) atom. In the second O site, O(10) is bonded to one Tm(1), one Tm(2), one Cu(1), and one Ge(2) atom to form a mixture of distorted edge and corner-sharing OTm2CuGe trigonal pyramids. In the third O site, O(1) is bonded in a 5-coordinate geometry to one Tm(1), one Tm(2), two equivalent Cu(1), and one Ge(2) atom. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Tm(1), one Tm(2), one Cu(1), and one Ge(1) atom. In the fifth O site, O(3) is bonded in a trigonal planar geometry to two equivalent Tm(1) and one Ge(3) atom. In the sixth O site, O(4) is bonded to one Tm(1), one Tm(2), one Cu(1), and one Ge(2) atom to form a mixture of distorted edge and corner-sharing OTm2CuGe trigonal pyramids. In the seventh O site, O(5) is bonded in a 4-coordinate geometry to one Tm(1), one Tm(2), one Ge(2), and one Ge(3) atom. In the eighth O site, O(6) is bonded in a trigonal planar geometry to two equivalent Tm(1) and one Ge(1) atom. In the ninth O site, O(7) is bonded in a trigonal planar geometry to two equivalent Tm(2) and one Ge(3) atom. In the tenth O site, O(8) is bonded to one Tm(1), one Tm(2), one Cu(1), and one Ge(2) atom to form a mixture of edge and corner-sharing OTm2CuGe trigonal pyramids.