KPrF4 crystallizes in the orthorhombic Pnma space group. K(1) is bonded in a 7-coordinate geometry to one F(4), two equivalent F(2), and four equivalent F(1) atoms. Pr(1) is bonded in a 9-coordinate geometry to one F(1), two equivalent F(2), three equivalent F(3), and three equivalent F(4) atoms. There are four inequivalent F sites. In the first F site, F(1) is bonded in a 5-coordinate geometry to four equivalent K(1) and one Pr(1) atom. In the second F site, F(2) is bonded to two equivalent K(1) and two equivalent Pr(1) atoms to form FK2Pr2 tetrahedra that share corners with four equivalent F(2)K2Pr2 tetrahedra, corners with six equivalent F(4)KPr3 tetrahedra, and  an edgeedge with one F(4)KPr3 tetrahedra. In the third F site, F(3) is bonded in a trigonal non-coplanar geometry to three equivalent Pr(1) atoms. In the fourth F site, F(4) is bonded to one K(1) and three equivalent Pr(1) atoms to form FKPr3 tetrahedra that share corners with two equivalent F(4)KPr3 tetrahedra, corners with six equivalent F(2)K2Pr2 tetrahedra,  an edgeedge with one F(2)K2Pr2 tetrahedra, and edges with two equivalent F(4)KPr3 tetrahedra.
KPrF4 crystallizes in the orthorhombic Pnma space group. K(1) is bonded in a 7-coordinate geometry to one F(4), two equivalent F(2), and four equivalent F(1) atoms. The K(1)-F(4) bond length is 2.61 Å. There is one shorter (2.60 Å) and one longer (2.63 Å) K(1)-F(2) bond length. There are two shorter (2.70 Å) and two longer (2.74 Å) K(1)-F(1) bond lengths. Pr(1) is bonded in a 9-coordinate geometry to one F(1), two equivalent F(2), three equivalent F(3), and three equivalent F(4) atoms. The Pr(1)-F(1) bond length is 2.32 Å. Both Pr(1)-F(2) bond lengths are 2.39 Å. There is one shorter (2.44 Å) and two longer (2.52 Å) Pr(1)-F(3) bond lengths. There is one shorter (2.43 Å) and two longer (2.48 Å) Pr(1)-F(4) bond lengths. There are four inequivalent F sites. In the first F site, F(1) is bonded in a 5-coordinate geometry to four equivalent K(1) and one Pr(1) atom. In the second F site, F(2) is bonded to two equivalent K(1) and two equivalent Pr(1) atoms to form FK2Pr2 tetrahedra that share corners with four equivalent F(2)K2Pr2 tetrahedra, corners with six equivalent F(4)KPr3 tetrahedra, and  an edgeedge with one F(4)KPr3 tetrahedra. In the third F site, F(3) is bonded in a trigonal non-coplanar geometry to three equivalent Pr(1) atoms. In the fourth F site, F(4) is bonded to one K(1) and three equivalent Pr(1) atoms to form FKPr3 tetrahedra that share corners with two equivalent F(4)KPr3 tetrahedra, corners with six equivalent F(2)K2Pr2 tetrahedra,  an edgeedge with one F(2)K2Pr2 tetrahedra, and edges with two equivalent F(4)KPr3 tetrahedra.