The employment of relativistic adapted Gaussian basis sets in Douglas–Kroll–Hess scalar calculations with diatomic molecules |
| |
Authors: | Roberto LA Haiduke Moacyr Comar JrAlbérico BF da Silva |
| |
Institution: | Departamento de Química e Física Molecular, Instituto de Química de São Carlos, Universidade de São Paulo, C.P. 780, 13560-970, São Carlos, SP, Brazil |
| |
Abstract: | The prolapse-free relativistic adapted Gaussian basis sets (RAGBSs), developed by our research group on the basis of the four-component approach, are used for the first time in Douglas–Kroll–Hess 2nd order scalar relativistic calculations (DKH2) of simple diatomic molecules containing Hydrogen and the halogens from Fluorine up to Iodine: HX and X2, where X = F, Cl, Br, and I. To this end, the RAGBSs were contracted with the general contraction scheme to triple-, quadruple-, and quintuple-zeta sets. Polarization functions were also added to the basis sets by optimization with the configuration interaction method including single and double excitations into the DKH2 environment, DKH2-CISD. The molecular properties were then calculated with the coupled cluster electronic correlation treatment and the DKH2 scalar relativistic method, DKH2-CCSD(T), and indicated that our RAGBSs should be contracted as quadruple-zeta basis sets. The results achieved with the DKH2-CCSD(T) calculations and the selected quadruple-zeta RAGBSs are able to reproduce the experimental data of equilibrium distances, dissociation energies, and harmonic vibrational frequencies with root-mean-square (rms) errors of 0.015 Å, 3.6 kcal mol−1, and 21.7 cm−1, respectively. |
| |
Keywords: | Gaussian-type orbitals Relativistic effects Adapted basis sets Douglas&ndash Kroll&ndash Hess Relativistic scalar methods |
本文献已被 ScienceDirect 等数据库收录! |
|