Error-Balanced Segmented Contracted Basis Sets of Double-ζ to Quadruple-ζ Valence Quality for the Lanthanides.

For lanthanides, segmented contracted Gaussian basis sets of double-ζ valence to quadruple-ζ valence quality are presented, with two different polarization sets for each level of quality. The bases are designed for use in connection with small-core Wood–Boring effective core potentials. A set of compounds representing most lanthanides in their common oxidation states is used to assess the quality. Parameters investigated were atomization energies, dipole moments, and structure parameters for Hartree–Fock, density functional, and correlated (Moller–Plesset) methods. So, the “def2” basis set series is extended to lanthanides with errors that are very similar to those previously obtained for the other elements with this type of basis set. Furthermore, for lanthanides, auxiliary bases for density fitting of Coulomb and Hartree–Fock exchange matrices are presented and tested.