Assessment of DFT Methods for Transition Metals with the TMC151 Compilation of Data Sets and Comparison with Accuracies for Main-Group Chemistry

In the present study,
we have gathered a collection (that we term TMC151) of accurate reference
data for transition-metal reactions for the assessment of quantum
chemistry methods. It comprises diatomic dissociation energies and
reaction energies and barriers for prototypical transition-metal reactions.
Our assessment of a diverse range of different types of DFT methods
shows that the most accurate functionals include ωB97M-V, ωB97X-V,
MN15, and B97M-rV. Notably, they have also been previously validated
to be highly robust for main-group chemistry. Nevertheless, even these
methods show substantially worse accuracies for transition metals
than for main-group chemistry. For less accurate methods, there is
not a good correlation between their accuracies for main-group and
transition-metal chemistries. Thus, in the development of new DFT,
it is important to assess the accuracies for both types of data. In
this regard, we have formulated the TMC34 model for efficient assessment
of the performance for transition metals, which complements our previously
developed MG8 model for main-group chemistry. Together, they provide
a cost-effective means for initial assessment of new methodologies.