[{"from": "human", "value": "Describe this molecule. [13C][=Branch1][C][=O][=O]"}, {"from": "gpt", "value": "The molecule is a (13)C-modified compound that is carbon dioxide in which the carbon is present as its (13)C isotope. It has a role as a diagnostic agent. It is a (13)C-modified compound, a one-carbon compound, a carbon oxide and a gas molecular entity."}]