[{"from": "human", "value": "Provide a description of this molecule. [C][O][C][=Branch1][C][=O][C][C][C][=Branch1][C][=O][O]"}, {"from": "gpt", "value": "The molecule is a dicarboxylic acid monoester that is succinic acid in which one of the carboxy groups has been converted to its methyl ester. It is a dicarboxylic acid monoester and a hemisuccinate."}]