[{"from": "human", "value": "Based on the given information, design a molecule that meets the desired specifications. The molecule is a dicarboxylic acid dianion resulting from the removal of a proton from both of the carboxylic acid groups of ethylmalonic acid. It is a dicarboxylic acid dianion and an ethylmalonate. It is a conjugate base of an ethylmalonic acid."}, {"from": "gpt", "value": "[C][C][C][Branch1][=Branch1][C][=Branch1][C][=O][O-1][C][=Branch1][C][=O][O-1]"}]