Segmented all-electron basis sets of triple zeta quality for the lanthanides: application to structure calculations...

Nonrelativistic and relativistic (Douglas-Kroll-Hess, DKH) segmented all-electron Gaussian basis sets of valence triple zeta quality plus polarization functions (TZP) for the lanthanides were developed. As some atomic and molecular properties depend on a good description of the electrons far from the nuclei, these basis sets are augmented with diffuse functions, giving rise to the augmented TZP (ATZP) and ATZP-DKH basis sets. At the DKH level of theory, the B3LYP hybrid functional in conjunction with the TZP-DKH basis set were used to calculate the atomic charges and valence orbital populations of the lanthanide and oxygen atoms, the bond lengths, and the equilibrium dissociation energies of lanthanide monoxides. The DKH-B3LYP/ATZP-DKH polarizability of Yb and the DKH-M06/TZP-DKH first ionization energies of the lanthanides are also reported. Compared with the values obtained with a larger all-electron basis set, and theoretical and experimental data found in the literature, data obtained by our compact basis sets are verified to be accurate and reliable. Unlike effective core potential valence basis sets, our basis sets can also be employed in molecular property calculations that involve the simultaneous treatment of core and valence electrons. Graphical abstract ᅟ.