Ca3Ni7B2 crystallizes in the trigonal R-3m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 12-coordinate geometry to one Ca(2), three equivalent Ni(2), and nine equivalent Ni(1) atoms. In the second Ca site, Ca(2) is bonded in a 20-coordinate geometry to two equivalent Ca(1), twelve equivalent Ni(1), and six equivalent B(1) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a distorted L-shaped geometry to two equivalent Ca(2), three equivalent Ca(1), one Ni(2), and two equivalent B(1) atoms. In the second Ni site, Ni(2) is bonded to six equivalent Ca(1) and six equivalent Ni(1) atoms to form edge-sharing NiCa6Ni6 cuboctahedra. B(1) is bonded in a 6-coordinate geometry to three equivalent Ca(2) and six equivalent Ni(1) atoms.
Ca3Ni7B2 crystallizes in the trigonal R-3m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 12-coordinate geometry to one Ca(2), three equivalent Ni(2), and nine equivalent Ni(1) atoms. The Ca(1)-Ca(2) bond length is 3.06 Å. All Ca(1)-Ni(2) bond lengths are 2.98 Å. There are three shorter (3.02 Å) and six longer (3.07 Å) Ca(1)-Ni(1) bond lengths. In the second Ca site, Ca(2) is bonded in a 20-coordinate geometry to two equivalent Ca(1), twelve equivalent Ni(1), and six equivalent B(1) atoms. All Ca(2)-Ni(1) bond lengths are 2.89 Å. All Ca(2)-B(1) bond lengths are 2.95 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a distorted L-shaped geometry to two equivalent Ca(2), three equivalent Ca(1), one Ni(2), and two equivalent B(1) atoms. The Ni(1)-Ni(2) bond length is 2.59 Å. There is one shorter (2.00 Å) and one longer (2.02 Å) Ni(1)-B(1) bond length. In the second Ni site, Ni(2) is bonded to six equivalent Ca(1) and six equivalent Ni(1) atoms to form edge-sharing NiCa6Ni6 cuboctahedra. B(1) is bonded in a 6-coordinate geometry to three equivalent Ca(2) and six equivalent Ni(1) atoms.