KGaP2O7 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 10-coordinate geometry to one O(1), one O(4), one O(5), one O(7), two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms. Ga(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form GaO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent 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 three equivalent Ga(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 18-48°. In the second P site, P(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Ga(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 20-54°. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a distorted bent 150 degrees geometry to one K(1), one Ga(1), and one P(2) atom. In the second O site, O(6) is bonded in a 2-coordinate geometry to two equivalent K(1), one Ga(1), and one P(2) atom. In the third O site, O(7) is bonded in a 3-coordinate geometry to one K(1), one Ga(1), and one P(2) atom. In the fourth O site, O(1) is bonded in a bent 120 degrees geometry to one K(1), one P(1), and one P(2) atom. In the fifth O site, O(2) is bonded in a 4-coordinate geometry to two equivalent K(1), one Ga(1), and one P(1) atom. In the sixth O site, O(3) is bonded in a 2-coordinate geometry to two equivalent K(1), one Ga(1), and one P(1) atom. In the seventh O site, O(4) is bonded in a distorted linear geometry to one K(1), one Ga(1), and one P(1) atom.
KGaP2O7 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 10-coordinate geometry to one O(1), one O(4), one O(5), one O(7), two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms. The K(1)-O(1) bond length is 3.13 Å. The K(1)-O(4) bond length is 3.18 Å. The K(1)-O(5) bond length is 3.04 Å. The K(1)-O(7) bond length is 2.76 Å. There is one shorter (2.73 Å) and one longer (2.90 Å) K(1)-O(2) bond length. There is one shorter (2.75 Å) and one longer (2.88 Å) K(1)-O(3) bond length. There is one shorter (3.02 Å) and one longer (3.22 Å) K(1)-O(6) bond length. Ga(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form GaO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. The Ga(1)-O(2) bond length is 1.97 Å. The Ga(1)-O(3) bond length is 1.97 Å. The Ga(1)-O(4) bond length is 1.92 Å. The Ga(1)-O(5) bond length is 1.97 Å. The Ga(1)-O(6) bond length is 1.96 Å. The Ga(1)-O(7) bond length is 1.99 Å. 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 three equivalent Ga(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 18-48°. The P(1)-O(1) bond length is 1.61 Å. The P(1)-O(2) bond length is 1.52 Å. The P(1)-O(3) bond length is 1.52 Å. The P(1)-O(4) bond length is 1.49 Å. In the second P site, P(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Ga(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 20-54°. The P(2)-O(1) bond length is 1.61 Å. The P(2)-O(5) bond length is 1.51 Å. The P(2)-O(6) bond length is 1.52 Å. The P(2)-O(7) bond length is 1.52 Å. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a distorted bent 150 degrees geometry to one K(1), one Ga(1), and one P(2) atom. In the second O site, O(6) is bonded in a 2-coordinate geometry to two equivalent K(1), one Ga(1), and one P(2) atom. In the third O site, O(7) is bonded in a 3-coordinate geometry to one K(1), one Ga(1), and one P(2) atom. In the fourth O site, O(1) is bonded in a bent 120 degrees geometry to one K(1), one P(1), and one P(2) atom. In the fifth O site, O(2) is bonded in a 4-coordinate geometry to two equivalent K(1), one Ga(1), and one P(1) atom. In the sixth O site, O(3) is bonded in a 2-coordinate geometry to two equivalent K(1), one Ga(1), and one P(1) atom. In the seventh O site, O(4) is bonded in a distorted linear geometry to one K(1), one Ga(1), and one P(1) atom.