Abstract: | Ca3Au6.61Ga4.39 was synthesized by reacting the elements in a glassy carbon crucible under argon in a water‐cooled sample chamber in a high‐frequency furnace. The compound crystallizes with a new hexagonal structure type, space group P63/mmc: Z = 2, a = 926.6(2), c = 733.1(2) pm, wR2 = 0.0832, 328 F values and 20 variables. This structure type consists of a remarkably complex three‐dimensional Au6.61Ga4.39] network with significant Au–Au, Au–Ga, and Ga–Ga interactions. The calcium atoms are located within slightly distorted hexagonal channels of the gold–gallium network. The structural relations to the AlB2 and Er2RhSi3 type structures are discussed. |