[{"from": "human", "value": "Generate a molecule based on the given description. The molecule appears as a colorless crystalline solid. Soluble in water and denser than water. Toxic by ingestion and inhalation. An irritant."}, {"from": "gpt", "value": "[O][As][=Branch1][C][=O][Branch1][C][O][O-1].[K+1]"}]