PrCo5H4 crystallizes in the orthorhombic Cmmm space group. Pr(1) is bonded in a 8-coordinate geometry to four equivalent H(1) and four equivalent H(2) atoms. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a water-like geometry to two equivalent Co(3) and two equivalent H(2) atoms. In the second Co site, Co(2) is bonded in a distorted square co-planar geometry to two equivalent Co(3), two equivalent H(1), and two equivalent H(2) atoms. In the third Co site, Co(3) is bonded in a 8-coordinate geometry to four equivalent Co(1) and four equivalent Co(2) atoms. There are two inequivalent H sites. In the first H site, H(1) is bonded to two equivalent Pr(1) and two equivalent Co(2) atoms to form HPr2Co2 tetrahedra that share corners with four equivalent H(2)Pr2Co4 octahedra, corners with six equivalent H(1)Pr2Co2 tetrahedra, edges with four equivalent H(2)Pr2Co4 octahedra, and  an edgeedge with one H(1)Pr2Co2 tetrahedra. The corner-sharing octahedral tilt angles are 63°. In the second H site, H(2) is bonded to two equivalent Pr(1), two equivalent Co(1), and two equivalent Co(2) atoms to form distorted HPr2Co4 octahedra that share corners with six equivalent H(2)Pr2Co4 octahedra, corners with four equivalent H(1)Pr2Co2 tetrahedra, edges with two equivalent H(2)Pr2Co4 octahedra, and edges with four equivalent H(1)Pr2Co2 tetrahedra. The corner-sharing octahedral tilt angles range from 0-64°.
PrCo5H4 crystallizes in the orthorhombic Cmmm space group. Pr(1) is bonded in a 8-coordinate geometry to four equivalent H(1) and four equivalent H(2) atoms. All Pr(1)-H(1) bond lengths are 2.39 Å. All Pr(1)-H(2) bond lengths are 2.60 Å. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a water-like geometry to two equivalent Co(3) and two equivalent H(2) atoms. Both Co(1)-Co(3) bond lengths are 2.35 Å. Both Co(1)-H(2) bond lengths are 1.70 Å. In the second Co site, Co(2) is bonded in a distorted square co-planar geometry to two equivalent Co(3), two equivalent H(1), and two equivalent H(2) atoms. Both Co(2)-Co(3) bond lengths are 2.60 Å. Both Co(2)-H(1) bond lengths are 1.65 Å. Both Co(2)-H(2) bond lengths are 2.02 Å. In the third Co site, Co(3) is bonded in a 8-coordinate geometry to four equivalent Co(1) and four equivalent Co(2) atoms. There are two inequivalent H sites. In the first H site, H(1) is bonded to two equivalent Pr(1) and two equivalent Co(2) atoms to form HPr2Co2 tetrahedra that share corners with four equivalent H(2)Pr2Co4 octahedra, corners with six equivalent H(1)Pr2Co2 tetrahedra, edges with four equivalent H(2)Pr2Co4 octahedra, and  an edgeedge with one H(1)Pr2Co2 tetrahedra. The corner-sharing octahedral tilt angles are 63°. In the second H site, H(2) is bonded to two equivalent Pr(1), two equivalent Co(1), and two equivalent Co(2) atoms to form distorted HPr2Co4 octahedra that share corners with six equivalent H(2)Pr2Co4 octahedra, corners with four equivalent H(1)Pr2Co2 tetrahedra, edges with two equivalent H(2)Pr2Co4 octahedra, and edges with four equivalent H(1)Pr2Co2 tetrahedra. The corner-sharing octahedral tilt angles range from 0-64°.