Sm2Ge2O7 crystallizes in the triclinic P-1 space group. There are four inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(9) atom. In the second Sm site, Sm(2) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(3), one O(4), one O(6), and two equivalent O(2) atoms. In the third Sm site, Sm(3) is bonded in a 6-coordinate geometry to one O(11), one O(12), one O(13), one O(5), one O(8), and one O(9) atom. In the fourth Sm site, Sm(4) is bonded in a 8-coordinate geometry to one O(10), one O(11), one O(13), one O(6), one O(7), one O(9), and two equivalent O(12) atoms. There are four inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(5), and one O(6) atom. In the second Ge site, Ge(2) is bonded to one O(3), one O(4), one O(7), and one O(8) atom to form corner-sharing GeO4 tetrahedra. In the third Ge site, Ge(3) is bonded to one O(10), one O(12), one O(14), and one O(9) atom to form corner-sharing GeO4 tetrahedra. In the fourth Ge site, Ge(4) is bonded to one O(11), one O(13), one O(14), and one O(8) atom to form corner-sharing GeO4 tetrahedra. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Sm(1), one Sm(2), and one Ge(1) atom. In the second O site, O(2) is bonded to one Sm(1), two equivalent Sm(2), and one Ge(1) atom to form a mixture of distorted edge and corner-sharing OSm3Ge tetrahedra. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Sm(1), one Sm(2), and one Ge(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Sm(1), one Sm(2), and one Ge(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Sm(1), one Sm(3), and one Ge(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Sm(1), one Sm(2), one Sm(4), and one Ge(1) atom. In the seventh O site, O(7) is bonded in a 1-coordinate geometry to one Sm(1), one Sm(4), and one Ge(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Sm(3), one Ge(2), and one Ge(4) atom. In the ninth O site, O(9) is bonded to one Sm(1), one Sm(3), one Sm(4), and one Ge(3) atom to form distorted corner-sharing OSm3Ge tetrahedra. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Sm(2), one Sm(4), and one Ge(3) atom. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Sm(3), one Sm(4), and one Ge(4) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Sm(3), two equivalent Sm(4), and one Ge(3) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Sm(3), one Sm(4), and one Ge(4) atom. In the fourteenth O site, O(14) is bonded in a bent 120 degrees geometry to one Ge(3) and one Ge(4) atom.
Sm2Ge2O7 crystallizes in the triclinic P-1 space group. There are four inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(9) atom. The Sm(1)-O(1) bond length is 2.37 Å. The Sm(1)-O(2) bond length is 2.45 Å. The Sm(1)-O(3) bond length is 2.52 Å. The Sm(1)-O(4) bond length is 2.36 Å. The Sm(1)-O(5) bond length is 2.40 Å. The Sm(1)-O(6) bond length is 2.70 Å. The Sm(1)-O(7) bond length is 2.41 Å. The Sm(1)-O(9) bond length is 2.54 Å. In the second Sm site, Sm(2) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(3), one O(4), one O(6), and two equivalent O(2) atoms. The Sm(2)-O(1) bond length is 2.42 Å. The Sm(2)-O(10) bond length is 2.45 Å. The Sm(2)-O(3) bond length is 2.41 Å. The Sm(2)-O(4) bond length is 2.31 Å. The Sm(2)-O(6) bond length is 2.41 Å. There is one shorter (2.40 Å) and one longer (2.49 Å) Sm(2)-O(2) bond length. In the third Sm site, Sm(3) is bonded in a 6-coordinate geometry to one O(11), one O(12), one O(13), one O(5), one O(8), and one O(9) atom. The Sm(3)-O(11) bond length is 2.36 Å. The Sm(3)-O(12) bond length is 2.37 Å. The Sm(3)-O(13) bond length is 2.30 Å. The Sm(3)-O(5) bond length is 2.29 Å. The Sm(3)-O(8) bond length is 2.40 Å. The Sm(3)-O(9) bond length is 2.45 Å. In the fourth Sm site, Sm(4) is bonded in a 8-coordinate geometry to one O(10), one O(11), one O(13), one O(6), one O(7), one O(9), and two equivalent O(12) atoms. The Sm(4)-O(10) bond length is 2.37 Å. The Sm(4)-O(11) bond length is 2.37 Å. The Sm(4)-O(13) bond length is 2.30 Å. The Sm(4)-O(6) bond length is 2.30 Å. The Sm(4)-O(7) bond length is 2.60 Å. The Sm(4)-O(9) bond length is 2.48 Å. There is one shorter (2.56 Å) and one longer (2.81 Å) Sm(4)-O(12) bond length. There are four inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(5), and one O(6) atom. The Ge(1)-O(1) bond length is 1.74 Å. The Ge(1)-O(2) bond length is 1.79 Å. The Ge(1)-O(5) bond length is 1.73 Å. The Ge(1)-O(6) bond length is 1.76 Å. In the second Ge site, Ge(2) is bonded to one O(3), one O(4), one O(7), and one O(8) atom to form corner-sharing GeO4 tetrahedra. The Ge(2)-O(3) bond length is 1.74 Å. The Ge(2)-O(4) bond length is 1.73 Å. The Ge(2)-O(7) bond length is 1.76 Å. The Ge(2)-O(8) bond length is 1.85 Å. In the third Ge site, Ge(3) is bonded to one O(10), one O(12), one O(14), and one O(9) atom to form corner-sharing GeO4 tetrahedra. The Ge(3)-O(10) bond length is 1.73 Å. The Ge(3)-O(12) bond length is 1.76 Å. The Ge(3)-O(14) bond length is 1.80 Å. The Ge(3)-O(9) bond length is 1.77 Å. In the fourth Ge site, Ge(4) is bonded to one O(11), one O(13), one O(14), and one O(8) atom to form corner-sharing GeO4 tetrahedra. The Ge(4)-O(11) bond length is 1.72 Å. The Ge(4)-O(13) bond length is 1.74 Å. The Ge(4)-O(14) bond length is 1.80 Å. The Ge(4)-O(8) bond length is 1.78 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Sm(1), one Sm(2), and one Ge(1) atom. In the second O site, O(2) is bonded to one Sm(1), two equivalent Sm(2), and one Ge(1) atom to form a mixture of distorted edge and corner-sharing OSm3Ge tetrahedra. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Sm(1), one Sm(2), and one Ge(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Sm(1), one Sm(2), and one Ge(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Sm(1), one Sm(3), and one Ge(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Sm(1), one Sm(2), one Sm(4), and one Ge(1) atom. In the seventh O site, O(7) is bonded in a 1-coordinate geometry to one Sm(1), one Sm(4), and one Ge(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Sm(3), one Ge(2), and one Ge(4) atom. In the ninth O site, O(9) is bonded to one Sm(1), one Sm(3), one Sm(4), and one Ge(3) atom to form distorted corner-sharing OSm3Ge tetrahedra. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Sm(2), one Sm(4), and one Ge(3) atom. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Sm(3), one Sm(4), and one Ge(4) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Sm(3), two equivalent Sm(4), and one Ge(3) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Sm(3), one Sm(4), and one Ge(4) atom. In the fourteenth O site, O(14) is bonded in a bent 120 degrees geometry to one Ge(3) and one Ge(4) atom.