An element-resolved coupled cluster atomization energy data set ranging across the periodic table

We introduce the total atomization energy periodic table compass (TAE-PTComp), a collection of 67 atomization energy data sets, each specifically designed to probe various chemical environments of one particular element of the periodic table. In total, this set comprises 2097 carefully curated closed-shell, single-reference molecules containing up to 50 atoms, with an average of 31 structures per element-specific subset. The chemical space covered ranges from conventional covalent and coordination compounds to noncovalently bound clusters, extracted fragments of periodic crystalline structures, and artificial "mindless" molecules. Additionally, we include a balanced amount of charged species with charges of ±1. For each molecule, as well as its constituent atoms (and ions), we provide high-level coupled cluster reference energies. We therefore envision this benchmark as a resource for parameter fitting, validation, and testing of approximate density functional theory methods, semi-empirical models, and machine-learning interatomic potentials. An initial assessment of TAE-PTComp for a representative set of density functional approximations, together with the semi-empirical g-xTB method and the machine-learned Universal Model for Atoms (UMA), shows that this benchmark can efficiently differentiate between broadly robust methods, such as the range-separated hybrid ωB97M-V, and approaches that exhibit localized, element-specific failures, such as the hybrid M06-2X functional.