Pr2CuInSe5 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 9-coordinate geometry to one Cu(1), two equivalent Se(1), two equivalent Se(2), two equivalent Se(3), and two equivalent Se(5) atoms. In the second Pr site, Pr(2) is bonded in a 8-coordinate geometry to one Se(3), two equivalent Se(2), two equivalent Se(5), and three equivalent Se(4) atoms. Cu(1) is bonded to one Pr(1), one Se(2), and three equivalent Se(1) atoms to form distorted CuPrSe4 tetrahedra that share corners with two equivalent Se(1)Pr2InCu3 octahedra, corners with three equivalent In(1)Se6 octahedra, corners with two equivalent Se(5)Pr4In square pyramids, corners with two equivalent Cu(1)PrSe4 tetrahedra, corners with two equivalent Se(3)Pr3In2 trigonal bipyramids, corners with two equivalent Se(2)Pr4Cu trigonal bipyramids, and edges with two equivalent Cu(1)PrSe4 tetrahedra. The corner-sharing octahedral tilt angles range from 10-135°. In(1) is bonded to one Se(1), one Se(5), two equivalent Se(3), and two equivalent Se(4) atoms to form InSe6 octahedra that share corners with three equivalent Cu(1)PrSe4 tetrahedra and edges with two equivalent In(1)Se6 octahedra. There are five inequivalent Se sites. In the first Se site, Se(5) is bonded to two equivalent Pr(1), two equivalent Pr(2), and one In(1) atom to form SePr4In square pyramids that share corners with three equivalent Se(1)Pr2InCu3 octahedra, corners with two equivalent Cu(1)PrSe4 tetrahedra, corners with two equivalent Se(4)Pr3In2 trigonal bipyramids, corners with four equivalent Se(2)Pr4Cu trigonal bipyramids,  an edgeedge with one Se(1)Pr2InCu3 octahedra, edges with two equivalent Se(5)Pr4In square pyramids, edges with two equivalent Se(2)Pr4Cu trigonal bipyramids, edges with three equivalent Se(4)Pr3In2 trigonal bipyramids, and edges with four equivalent Se(3)Pr3In2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 2-37°. In the second Se site, Se(1) is bonded to two equivalent Pr(1), three equivalent Cu(1), and one In(1) atom to form distorted SePr2InCu3 octahedra that share corners with three equivalent Se(5)Pr4In square pyramids, corners with two equivalent Cu(1)PrSe4 tetrahedra, corners with two equivalent Se(3)Pr3In2 trigonal bipyramids, corners with two equivalent Se(4)Pr3In2 trigonal bipyramids, corners with four equivalent Se(2)Pr4Cu trigonal bipyramids, edges with four equivalent Se(1)Pr2InCu3 octahedra,  an edgeedge with one Se(5)Pr4In square pyramid, edges with two equivalent Se(3)Pr3In2 trigonal bipyramids, and  a faceface with one Se(2)Pr4Cu trigonal bipyramid. In the third Se site, Se(2) is bonded to two equivalent Pr(1), two equivalent Pr(2), and one Cu(1) atom to form distorted SePr4Cu trigonal bipyramids that share corners with four equivalent Se(1)Pr2InCu3 octahedra, corners with four equivalent Se(5)Pr4In square pyramids, corners with two equivalent Cu(1)PrSe4 tetrahedra, corners with two equivalent Se(3)Pr3In2 trigonal bipyramids, corners with four equivalent Se(4)Pr3In2 trigonal bipyramids, edges with two equivalent Se(5)Pr4In square pyramids,  an edgeedge with one Se(4)Pr3In2 trigonal bipyramid, edges with two equivalent Se(3)Pr3In2 trigonal bipyramids, edges with two equivalent Se(2)Pr4Cu trigonal bipyramids, and  a faceface with one Se(1)Pr2InCu3 octahedra. The corner-sharing octahedral tilt angles range from 58-66°. In the fourth Se site, Se(3) is bonded to one Pr(2), two equivalent Pr(1), and two equivalent In(1) atoms to form distorted SePr3In2 trigonal bipyramids that share corners with two equivalent Se(1)Pr2InCu3 octahedra, corners with two equivalent Cu(1)PrSe4 tetrahedra, corners with two equivalent Se(2)Pr4Cu trigonal bipyramids, corners with four equivalent Se(3)Pr3In2 trigonal bipyramids, corners with five equivalent Se(4)Pr3In2 trigonal bipyramids, edges with two equivalent Se(1)Pr2InCu3 octahedra, edges with four equivalent Se(5)Pr4In square pyramids,  an edgeedge with one Se(4)Pr3In2 trigonal bipyramid, and edges with two equivalent Se(2)Pr4Cu trigonal bipyramids. The corner-sharing octahedral tilt angles are 46°. In the fifth Se site, Se(4) is bonded to three equivalent Pr(2) and two equivalent In(1) atoms to form SePr3In2 trigonal bipyramids that share corners with two equivalent Se(1)Pr2InCu3 octahedra, corners with two equivalent Se(5)Pr4In square pyramids, corners with four equivalent Se(2)Pr4Cu trigonal bipyramids, corners with five equivalent Se(3)Pr3In2 trigonal bipyramids, edges with three equivalent Se(5)Pr4In square pyramids,  an edgeedge with one Se(3)Pr3In2 trigonal bipyramid,  an edgeedge with one Se(2)Pr4Cu trigonal bipyramid, and edges with four equivalent Se(4)Pr3In2 trigonal bipyramids. The corner-sharing octahedral tilt angles are 85°.
Pr2CuInSe5 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 9-coordinate geometry to one Cu(1), two equivalent Se(1), two equivalent Se(2), two equivalent Se(3), and two equivalent Se(5) atoms. The Pr(1)-Cu(1) bond length is 3.32 Å. Both Pr(1)-Se(1) bond lengths are 3.09 Å. Both Pr(1)-Se(2) bond lengths are 3.06 Å. There is one shorter (3.28 Å) and one longer (3.33 Å) Pr(1)-Se(3) bond length. Both Pr(1)-Se(5) bond lengths are 3.06 Å. In the second Pr site, Pr(2) is bonded in a 8-coordinate geometry to one Se(3), two equivalent Se(2), two equivalent Se(5), and three equivalent Se(4) atoms. The Pr(2)-Se(3) bond length is 3.32 Å. Both Pr(2)-Se(2) bond lengths are 3.04 Å. Both Pr(2)-Se(5) bond lengths are 3.08 Å. There are two shorter (3.09 Å) and one longer (3.14 Å) Pr(2)-Se(4) bond length. Cu(1) is bonded to one Pr(1), one Se(2), and three equivalent Se(1) atoms to form distorted CuPrSe4 tetrahedra that share corners with two equivalent Se(1)Pr2InCu3 octahedra, corners with three equivalent In(1)Se6 octahedra, corners with two equivalent Se(5)Pr4In square pyramids, corners with two equivalent Cu(1)PrSe4 tetrahedra, corners with two equivalent Se(3)Pr3In2 trigonal bipyramids, corners with two equivalent Se(2)Pr4Cu trigonal bipyramids, and edges with two equivalent Cu(1)PrSe4 tetrahedra. The corner-sharing octahedral tilt angles range from 10-135°. The Cu(1)-Se(2) bond length is 2.41 Å. There are two shorter (2.45 Å) and one longer (2.61 Å) Cu(1)-Se(1) bond length. In(1) is bonded to one Se(1), one Se(5), two equivalent Se(3), and two equivalent Se(4) atoms to form InSe6 octahedra that share corners with three equivalent Cu(1)PrSe4 tetrahedra and edges with two equivalent In(1)Se6 octahedra. The In(1)-Se(1) bond length is 2.74 Å. The In(1)-Se(5) bond length is 2.70 Å. Both In(1)-Se(3) bond lengths are 2.74 Å. Both In(1)-Se(4) bond lengths are 2.92 Å. There are five inequivalent Se sites. In the first Se site, Se(5) is bonded to two equivalent Pr(1), two equivalent Pr(2), and one In(1) atom to form SePr4In square pyramids that share corners with three equivalent Se(1)Pr2InCu3 octahedra, corners with two equivalent Cu(1)PrSe4 tetrahedra, corners with two equivalent Se(4)Pr3In2 trigonal bipyramids, corners with four equivalent Se(2)Pr4Cu trigonal bipyramids,  an edgeedge with one Se(1)Pr2InCu3 octahedra, edges with two equivalent Se(5)Pr4In square pyramids, edges with two equivalent Se(2)Pr4Cu trigonal bipyramids, edges with three equivalent Se(4)Pr3In2 trigonal bipyramids, and edges with four equivalent Se(3)Pr3In2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 2-37°. In the second Se site, Se(1) is bonded to two equivalent Pr(1), three equivalent Cu(1), and one In(1) atom to form distorted SePr2InCu3 octahedra that share corners with three equivalent Se(5)Pr4In square pyramids, corners with two equivalent Cu(1)PrSe4 tetrahedra, corners with two equivalent Se(3)Pr3In2 trigonal bipyramids, corners with two equivalent Se(4)Pr3In2 trigonal bipyramids, corners with four equivalent Se(2)Pr4Cu trigonal bipyramids, edges with four equivalent Se(1)Pr2InCu3 octahedra,  an edgeedge with one Se(5)Pr4In square pyramid, edges with two equivalent Se(3)Pr3In2 trigonal bipyramids, and  a faceface with one Se(2)Pr4Cu trigonal bipyramid. In the third Se site, Se(2) is bonded to two equivalent Pr(1), two equivalent Pr(2), and one Cu(1) atom to form distorted SePr4Cu trigonal bipyramids that share corners with four equivalent Se(1)Pr2InCu3 octahedra, corners with four equivalent Se(5)Pr4In square pyramids, corners with two equivalent Cu(1)PrSe4 tetrahedra, corners with two equivalent Se(3)Pr3In2 trigonal bipyramids, corners with four equivalent Se(4)Pr3In2 trigonal bipyramids, edges with two equivalent Se(5)Pr4In square pyramids,  an edgeedge with one Se(4)Pr3In2 trigonal bipyramid, edges with two equivalent Se(3)Pr3In2 trigonal bipyramids, edges with two equivalent Se(2)Pr4Cu trigonal bipyramids, and  a faceface with one Se(1)Pr2InCu3 octahedra. The corner-sharing octahedral tilt angles range from 58-66°. In the fourth Se site, Se(3) is bonded to one Pr(2), two equivalent Pr(1), and two equivalent In(1) atoms to form distorted SePr3In2 trigonal bipyramids that share corners with two equivalent Se(1)Pr2InCu3 octahedra, corners with two equivalent Cu(1)PrSe4 tetrahedra, corners with two equivalent Se(2)Pr4Cu trigonal bipyramids, corners with four equivalent Se(3)Pr3In2 trigonal bipyramids, corners with five equivalent Se(4)Pr3In2 trigonal bipyramids, edges with two equivalent Se(1)Pr2InCu3 octahedra, edges with four equivalent Se(5)Pr4In square pyramids,  an edgeedge with one Se(4)Pr3In2 trigonal bipyramid, and edges with two equivalent Se(2)Pr4Cu trigonal bipyramids. The corner-sharing octahedral tilt angles are 46°. In the fifth Se site, Se(4) is bonded to three equivalent Pr(2) and two equivalent In(1) atoms to form SePr3In2 trigonal bipyramids that share corners with two equivalent Se(1)Pr2InCu3 octahedra, corners with two equivalent Se(5)Pr4In square pyramids, corners with four equivalent Se(2)Pr4Cu trigonal bipyramids, corners with five equivalent Se(3)Pr3In2 trigonal bipyramids, edges with three equivalent Se(5)Pr4In square pyramids,  an edgeedge with one Se(3)Pr3In2 trigonal bipyramid,  an edgeedge with one Se(2)Pr4Cu trigonal bipyramid, and edges with four equivalent Se(4)Pr3In2 trigonal bipyramids. The corner-sharing octahedral tilt angles are 85°.