[{"from": "human", "value": "Based on the given information, design a molecule that meets the desired specifications. The molecule appears as a white crystalline solid. Denser than water. Contact may cause irritation to skin, eyes, and mucous membranes. May be toxic by ingestion and inhalation."}, {"from": "gpt", "value": "[C-1][#N].[C-1][#N].[K+1].[Cu+1]"}]