Gd2P4O13 crystallizes in the orthorhombic C222_1 space group. Gd(1) is bonded to one O(1), one O(4), one O(7), two equivalent O(5), and two equivalent O(6) atoms to form distorted GdO7 pentagonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, edges with two equivalent Gd(1)O7 pentagonal bipyramids, and  an edgeedge with one P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Gd(1)O7 pentagonal bipyramids,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(2)O4 tetrahedra. In the second P site, P(2) is bonded to one O(3), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Gd(1)O7 pentagonal bipyramids,  a cornercorner with one P(1)O4 tetrahedra, and  an edgeedge with one Gd(1)O7 pentagonal bipyramid. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Gd(1) and one P(2) atom. In the second O site, O(7) is bonded in a bent 150 degrees geometry to one Gd(1) and one P(2) atom. In the third O site, O(1) is bonded in a linear geometry to one Gd(1) and one P(1) atom. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent P(1) atoms. In the fifth O site, O(3) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the sixth O site, O(4) is bonded in a bent 150 degrees geometry to one Gd(1) and one P(1) atom. In the seventh O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Gd(1) and one P(2) atom.
Gd2P4O13 crystallizes in the orthorhombic C222_1 space group. Gd(1) is bonded to one O(1), one O(4), one O(7), two equivalent O(5), and two equivalent O(6) atoms to form distorted GdO7 pentagonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, edges with two equivalent Gd(1)O7 pentagonal bipyramids, and  an edgeedge with one P(2)O4 tetrahedra. The Gd(1)-O(1) bond length is 2.28 Å. The Gd(1)-O(4) bond length is 2.27 Å. The Gd(1)-O(7) bond length is 2.25 Å. There is one shorter (2.38 Å) and one longer (2.55 Å) Gd(1)-O(5) bond length. There is one shorter (2.36 Å) and one longer (2.41 Å) Gd(1)-O(6) bond length. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Gd(1)O7 pentagonal bipyramids,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(2)O4 tetrahedra. The P(1)-O(1) bond length is 1.48 Å. The P(1)-O(2) bond length is 1.58 Å. The P(1)-O(3) bond length is 1.58 Å. The P(1)-O(4) bond length is 1.49 Å. In the second P site, P(2) is bonded to one O(3), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Gd(1)O7 pentagonal bipyramids,  a cornercorner with one P(1)O4 tetrahedra, and  an edgeedge with one Gd(1)O7 pentagonal bipyramid. The P(2)-O(3) bond length is 1.61 Å. The P(2)-O(5) bond length is 1.53 Å. The P(2)-O(6) bond length is 1.52 Å. The P(2)-O(7) bond length is 1.49 Å. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Gd(1) and one P(2) atom. In the second O site, O(7) is bonded in a bent 150 degrees geometry to one Gd(1) and one P(2) atom. In the third O site, O(1) is bonded in a linear geometry to one Gd(1) and one P(1) atom. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent P(1) atoms. In the fifth O site, O(3) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the sixth O site, O(4) is bonded in a bent 150 degrees geometry to one Gd(1) and one P(1) atom. In the seventh O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Gd(1) and one P(2) atom.