[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule appears as a crystal or powder with a rich violet-brown or dark purple metallic sheen. Toxic by ingestion or inhalation of dust."}, {"from": "gpt", "value": "[NH4+1].[O-1][Mn][=Branch1][C][=O][=Branch1][C][=O][=O]"}]