[{"from": "human", "value": "Synthesize a molecule that matches the given characteristics. The molecule is a calcium phosphate. It contains a diphosphate(4-)."}, {"from": "gpt", "value": "[O-1][P][=Branch1][C][=O][Branch1][C][O-1][O][P][=Branch1][C][=O][Branch1][C][O-1][O-1].[Ca+2].[Ca+2]"}]