[{"from": "human", "value": "Generate a molecule based on the given description. The molecule is a white crystalline solid. It reacts violently with water and may ignite upon contact with air. It is toxic by ingestion. It is used to make other chemicals."}, {"from": "gpt", "value": "[Mg+2].[Mg+2].[Mg+2].[P-3].[P-3]"}]