(3.2.9) Barone : Sufficiently accurate molecular structures are a prerequisite for the computation of thermodynamic, kinetic, and spectroscopic properties. In this connection, the latestgeneration DFAs (hybrid and, especially, double hybrids) with dispersion corrections added perform a remarkable job for maingroup elements, in noncovalent complexes and for transition states. Furthermore, the remaining errors are rather systematic and can be corrected for by linear regression, depending only on the atomic numbers of the involved atoms. As a matter of fact, energies and properties can usually be calculated very accurately at DFT geometries with negligible errors provided that the functional and the basis set are properly selected. The situation is more involved for transition metals, where comprehensive benchmarks are still missing.