The crystal structure of calcium hexaboride is a cubic lattice with calcium at the cell centre and compact, regular octahedra of boron atoms linked at the vertices by B-B bonds to give a three-dimensional boron network. Each calcium has 24 nearest-neighbor boron atoms The calcium atoms are arranged in simple cubic packing so that there are holes between groups of eight calcium atoms situated at the vertices of a cube. The simple cubic structure is expanded by the introduction of the octahedral B groups and the structure is a CsCl-like packing of the calcium and hexaboride groups. Another way of describing calcium hexaboride is as having a metal and a B octahedral polymeric anions in a CsCl-type structure where the Calcium atoms occupy the Cs sites and the B octahedra in the Cl sites. The Ca-B bond length is 3.05 Å and the B-B bond length is 1.7 Å.
Ca NMR data contains δ at -56.0 ppm and δ at -41.3 ppm where δ is taken as peak max +0.85 width, the negative shift is due to the high coordination number.
Raman Data: Calcium hexaboride has three Raman peaks at 754.3, 1121.8, and 1246.9 cm due to the active modes A, E, and T respectively.
Observed Vibrational Frequencies cm : 1270(strong) from A stretch, 1154 (med.) and 1125(shoulder) from E stretch, 526, 520, 485, and 470 from F rotation, 775 (strong) and 762 (shoulder) from F bend, 1125 (strong) and 1095 (weak) from F bend, 330 and 250 from F translation, and 880 (med.) and 779 from F bend.