[{"from": "human", "value": "Generate a molecule based on the given description. The molecule appears as a crystalline solid or the solid dissolved in a liquid. Denser than water. Contact may irritate skin, eyes and mucous membranes. May be toxic by ingestion. Noncombustible, but accelerates the burning of combustible materials. Used to make other chemicals."}, {"from": "gpt", "value": "[N][=Branch1][C][=O][O-1].[N][=Branch1][C][=O][O-1].[Ni+2]"}]