The novel quaternary nitride-hydride Ca-6(2)6(2)6([Cr)N(]H was synthesized at 1000 C in sealed niobium or stainless steel tubes. It crystallizes in the space group R (3) over bar (No. 148, Z = 3) with lattice constants () a = 9.0042(2) and c = 9.1898(3) and contains the complex anion [Cr)N]11- with a short chromium-chromium bond length of 2.26 . To our knowledge, this is the first example of a non-nitrogen-bridged chromium-chromium dimer in an extended structure compound. Magnetic susceptibility measurements reveal the compound to be paramagnetic at room temperature and with a broad antiferromagnetic ordering centered around 55 K.