RESUMO
From the segmented all-electron basis set of double zeta valence quality plus polarization functions (DZP) for the elements from H to Xe, the zeroth-order regular approximation (ZORA) is used to generate a DZP-ZORA basis set, i.e., the contraction coefficients of the DZP set are re-optimized using the minimum ZORA energy criterion. To properly describe electrons distant from the nuclei, a diffuse function is added to each atomic symmetry (s, p, d, and f). The later basis set is designated as DZP-ZORA augmented. To test the effectiveness of the basis sets developed in this work, calculations of ionization energies and mean dipole polarizabilities of some elements are performed using the ZORA-CCSD(T) method. At the same level of theory, bond lengths, dissociation energies, and harmonic vibrational frequencies of some diatoms are also reported. Comparison with experimental data and recommended values available in the literature is made. Except for polarizability, scalar relativistic effects are estimated for the other properties. The performances of the ZORA and second-order Douglas-Kroll-Hess Hamiltonians are evaluated.
RESUMO
Non-relativistic and Douglas-Kroll-Hess (DKH) basis sets augmented with diffuse functions for He, Ca, Sr, Ba, and lanthanides are generated. These sets are appropriated to describe electrons away from the nuclei. Using the DKH augmented sets along with the B3LYP functional, bond lengths, dissociation energies, harmonic vibrational frequencies, adiabatic ionization potentials, adiabatic electron affinities, and dipole moments for CaH, SrH, and BaH are computed. These results agree well with the most recent experimental and benchmark theoretical data published in the literature. The DKH mean dipole polarizabilities reported in this work for some elements are close to the recommended values. Scalar relativistic effects are also estimated.