Tm2GeO5 crystallizes in the monoclinic C2/c space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms. In the second Tm site, Tm(2) is bonded in a 6-coordinate geometry to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms. Ge(1) is bonded in a tetrahedral geometry to one O(2), one O(3), one O(4), and one O(5) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Tm(1) and two equivalent Tm(2) atoms to form edge-sharing OTm4 tetrahedra. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to two equivalent Tm(2) and one Ge(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Tm(2), two equivalent Tm(1), and one Ge(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Tm(1), one Tm(2), and one Ge(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Tm(1) and one Ge(1) atom.
Tm2GeO5 crystallizes in the monoclinic C2/c space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms. The Tm(1)-O(4) bond length is 2.27 Å. There is one shorter (2.15 Å) and one longer (2.37 Å) Tm(1)-O(1) bond length. There is one shorter (2.33 Å) and one longer (2.61 Å) Tm(1)-O(3) bond length. There is one shorter (2.25 Å) and one longer (2.30 Å) Tm(1)-O(5) bond length. In the second Tm site, Tm(2) is bonded in a 6-coordinate geometry to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms. The Tm(2)-O(3) bond length is 2.23 Å. The Tm(2)-O(4) bond length is 2.24 Å. There is one shorter (2.16 Å) and one longer (2.29 Å) Tm(2)-O(1) bond length. There is one shorter (2.23 Å) and one longer (2.25 Å) Tm(2)-O(2) bond length. Ge(1) is bonded in a tetrahedral geometry to one O(2), one O(3), one O(4), and one O(5) atom. The Ge(1)-O(2) bond length is 1.75 Å. The Ge(1)-O(3) bond length is 1.77 Å. The Ge(1)-O(4) bond length is 1.74 Å. The Ge(1)-O(5) bond length is 1.75 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Tm(1) and two equivalent Tm(2) atoms to form edge-sharing OTm4 tetrahedra. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to two equivalent Tm(2) and one Ge(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Tm(2), two equivalent Tm(1), and one Ge(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Tm(1), one Tm(2), and one Ge(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Tm(1) and one Ge(1) atom.