Pr(Ni2B)6 crystallizes in the orthorhombic Cmc2_1 space group. Pr(1) is bonded in a 24-coordinate geometry to one Ni(1), one Ni(2), two equivalent Ni(3), two equivalent Ni(7), four equivalent Ni(4), four equivalent Ni(5), four equivalent Ni(6), one B(1), one B(2), two equivalent B(3), and two equivalent B(4) atoms. There are seven inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 3-coordinate geometry to one Pr(1), one B(1), and two equivalent B(3) atoms. In the second Ni site, Ni(2) is bonded in a distorted T-shaped geometry to one Pr(1), one B(2), and two equivalent B(4) atoms. In the third Ni site, Ni(3) is bonded to one Pr(1), one B(1), one B(2), one B(3), and one B(4) atom to form distorted face-sharing NiPrB4 tetrahedra. In the fourth Ni site, Ni(4) is bonded in a 3-coordinate geometry to two equivalent Pr(1), one B(1), one B(3), and one B(4) atom. In the fifth Ni site, Ni(5) is bonded in a 4-coordinate geometry to two equivalent Pr(1), one B(2), one B(3), and two equivalent B(4) atoms. In the sixth Ni site, Ni(6) is bonded in a 4-coordinate geometry to two equivalent Pr(1), one B(1), one B(4), and two equivalent B(3) atoms. In the seventh Ni site, Ni(7) is bonded in a 3-coordinate geometry to one Pr(1), one B(2), one B(3), and one B(4) atom. There are four inequivalent B sites. In the first B site, B(1) is bonded in a 8-coordinate geometry to one Pr(1), one Ni(1), two equivalent Ni(3), two equivalent Ni(4), and two equivalent Ni(6) atoms. In the second B site, B(2) is bonded in a 7-coordinate geometry to one Pr(1), one Ni(2), two equivalent Ni(3), two equivalent Ni(5), and two equivalent Ni(7) atoms. In the third B site, B(3) is bonded in a 7-coordinate geometry to one Pr(1), one Ni(1), one Ni(3), one Ni(4), one Ni(5), one Ni(7), and two equivalent Ni(6) atoms. In the fourth B site, B(4) is bonded in a 7-coordinate geometry to one Pr(1), one Ni(2), one Ni(3), one Ni(4), one Ni(6), one Ni(7), and two equivalent Ni(5) atoms.
Pr(Ni2B)6 crystallizes in the orthorhombic Cmc2_1 space group. Pr(1) is bonded in a 24-coordinate geometry to one Ni(1), one Ni(2), two equivalent Ni(3), two equivalent Ni(7), four equivalent Ni(4), four equivalent Ni(5), four equivalent Ni(6), one B(1), one B(2), two equivalent B(3), and two equivalent B(4) atoms. The Pr(1)-Ni(1) bond length is 3.09 Å. The Pr(1)-Ni(2) bond length is 3.07 Å. Both Pr(1)-Ni(3) bond lengths are 3.12 Å. Both Pr(1)-Ni(7) bond lengths are 3.05 Å. There are two shorter (3.16 Å) and two longer (3.37 Å) Pr(1)-Ni(4) bond lengths. There are two shorter (3.19 Å) and two longer (3.33 Å) Pr(1)-Ni(5) bond lengths. There are two shorter (3.20 Å) and two longer (3.27 Å) Pr(1)-Ni(6) bond lengths. The Pr(1)-B(1) bond length is 3.03 Å. The Pr(1)-B(2) bond length is 3.09 Å. Both Pr(1)-B(3) bond lengths are 3.14 Å. Both Pr(1)-B(4) bond lengths are 3.27 Å. There are seven inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 3-coordinate geometry to one Pr(1), one B(1), and two equivalent B(3) atoms. The Ni(1)-B(1) bond length is 2.16 Å. Both Ni(1)-B(3) bond lengths are 2.07 Å. In the second Ni site, Ni(2) is bonded in a distorted T-shaped geometry to one Pr(1), one B(2), and two equivalent B(4) atoms. The Ni(2)-B(2) bond length is 2.05 Å. Both Ni(2)-B(4) bond lengths are 1.99 Å. In the third Ni site, Ni(3) is bonded to one Pr(1), one B(1), one B(2), one B(3), and one B(4) atom to form distorted face-sharing NiPrB4 tetrahedra. The Ni(3)-B(1) bond length is 2.05 Å. The Ni(3)-B(2) bond length is 2.03 Å. The Ni(3)-B(3) bond length is 2.08 Å. The Ni(3)-B(4) bond length is 1.98 Å. In the fourth Ni site, Ni(4) is bonded in a 3-coordinate geometry to two equivalent Pr(1), one B(1), one B(3), and one B(4) atom. The Ni(4)-B(1) bond length is 2.01 Å. The Ni(4)-B(3) bond length is 2.04 Å. The Ni(4)-B(4) bond length is 2.09 Å. In the fifth Ni site, Ni(5) is bonded in a 4-coordinate geometry to two equivalent Pr(1), one B(2), one B(3), and two equivalent B(4) atoms. The Ni(5)-B(2) bond length is 2.08 Å. The Ni(5)-B(3) bond length is 2.01 Å. There is one shorter (2.02 Å) and one longer (2.10 Å) Ni(5)-B(4) bond length. In the sixth Ni site, Ni(6) is bonded in a 4-coordinate geometry to two equivalent Pr(1), one B(1), one B(4), and two equivalent B(3) atoms. The Ni(6)-B(1) bond length is 2.08 Å. The Ni(6)-B(4) bond length is 2.04 Å. There is one shorter (2.01 Å) and one longer (2.11 Å) Ni(6)-B(3) bond length. In the seventh Ni site, Ni(7) is bonded in a 3-coordinate geometry to one Pr(1), one B(2), one B(3), and one B(4) atom. The Ni(7)-B(2) bond length is 2.07 Å. The Ni(7)-B(3) bond length is 2.04 Å. The Ni(7)-B(4) bond length is 2.12 Å. There are four inequivalent B sites. In the first B site, B(1) is bonded in a 8-coordinate geometry to one Pr(1), one Ni(1), two equivalent Ni(3), two equivalent Ni(4), and two equivalent Ni(6) atoms. In the second B site, B(2) is bonded in a 7-coordinate geometry to one Pr(1), one Ni(2), two equivalent Ni(3), two equivalent Ni(5), and two equivalent Ni(7) atoms. In the third B site, B(3) is bonded in a 7-coordinate geometry to one Pr(1), one Ni(1), one Ni(3), one Ni(4), one Ni(5), one Ni(7), and two equivalent Ni(6) atoms. In the fourth B site, B(4) is bonded in a 7-coordinate geometry to one Pr(1), one Ni(2), one Ni(3), one Ni(4), one Ni(6), one Ni(7), and two equivalent Ni(5) atoms.