The MultiXC-QM9 data set significantly expands upon the well-established QM9 data set for studying small molecules. While QM9 focuses on a single functional (B3LYP) and basis set, MultiXC-QM9 offers a richer resource, encompassing 76 different DFT functionals alongside three basis sets and a complementary semi-empirical method (GFN2-xTB). Beyond molecular energies, MultiXC-QM9 provides energies for all possible monomolecular interconversions (A↔B type) within the QM9 data set, calculated using the same methodology as the molecular energies. Additionally, the data set includes information on bond changes associated with these 162 million reactions.