Alkaline earth octacarbonyl complex
Alkaline earth octacarbonyl complexes are a class of neutral compounds that have the general formula M(CO)8 where M is a heavy Group 2 element (Ca, Sr, or Ba). The metal center has a formal oxidation state of 0 and the complex has a high level of symmetry belonging to the cubic Oh point group.
Source: Wikipedia — Alkaline earth octacarbonyl complex (CC BY-SA 4.0)