The development of new phosphate materials has attracted huge attention because of their promising applications as electrode materials and solid-state electrolytes for next-generation batteries. Several phosphates were elaborated and structurally investigated, such as the NASICON and alluaudite families, which show promising structural features permitting electrochemical activity as electrodes for rechargeable Li/Na batteries. In the context of the elaboration and structural investigation of novel alluaudite phosphates, we report on the crystal growth and the structural investigation of a new sodium, cobalt, and chromium-based phosphate, Na_1.67Co_2.45Cr_0.78(PO₄)₃, with an alluaudite-type structure. This phosphate has been produced using a solid-state technique and its structure has been elucidated thanks to single-crystal X-ray diffraction (XRD) data. The title compound crystallizes in space group C2/c of the monoclinic system with the lattice parameters a = 11.7538 (3) Å, b = 12.3671 (3) Å, c = 6.4180 (2) Å, and β = 114.022 (10)°. Its structure is formed by infinite chains, which are in turn created from edge-sharing (Co1,Cr1)₂O₁₀ units and Co₂O₆ octahedra. These infinite chains are bonded together by the PO₄ tetrahedra, resulting in a three-dimensional framework with two different kinds of hexagonal tunnels where Na+ and Na+ /Co2+ cations can be found.

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