[{"from": "human", "value": "Based on the given information, design a molecule that meets the desired specifications. The molecule is a magnesium salt with formula CMgO3. Its hydrated forms, particularly the di-, tri-, and tetrahydrates occur as minerals. It has a role as an antacid and a fertilizer. It is a magnesium salt, a carbonate salt, a one-carbon compound and an organic magnesium salt."}, {"from": "gpt", "value": "[C][=Branch1][C][=O][Branch1][C][O-1][O-1].[Mg+2]"}]