Conjuntos de bases gaussianas de qualidade quádrupla zeta de valência para os átomos de Rb até Xe

• Autor(a) principal: Ceolin, Geovane de Araujo
• Data de Publicação: 2013
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/7483
• topic: Hatree fock; Coupled cluster; Métodos Ab Initio; Física; Conjuntos de bases gaussianas (Mecânica quântica); 53

All-electron segmented contracted quadruple zeta valence plus polarization function (QZP) basis sets for the elements Rb-Xe were constructed to be used in conjunction with the non-relativistic and Douglas-Kroll-Hess (DKH) Hamiltonians. The QZP-DKH set is obtained from the original QZP basis set, i.e., the values of the contraction coefficients were reoptimized using the relativistic DKH Hamiltonian. This extends earlier works on segmented contracted QZ basis set for atoms H-Kr. At the Coupled Cluster level of theory, the convergence of atomic ionization energy as well as molecular spectroscopic constants as a function of basis set size is examined. Additional improvements on spectroscopic constants were achieved by applying corrections due to core-valence correlation and spin-orbit effects. This leads to estimates for the spectroscopic constants of various diatomics in gaseous phase. One verifies that the experimental and benchmark theoretical bond lengths, dissociation energies, and harmonic vibrational frequencies can be reproduced well with the QZP-DKH set. Augmented Gaussian basis set of quadruple zeta valence quality plus polarization functions for the atoms Rb and from Y to Xe is presented. It was were constructed from the all-electron unaugmented set by addition of diffuse functions (s, p, d, f, g, and h symmetries) that were optimized for the anion ground states. From this set, Hartree-Fock, second-order Mfller-Plesset perturbation theory, and density functional theory electric dipole moment and polarizabilities for a sample of molecules as well as for Agn (n = 4) clusters were calculated and compared with theoretical and experimental values available in the literature