The low-lying electronic states of cerium monoxide CeO: ab initio calculations using energy-adjusted pseudopotentials and spin-orbit operators

• Published in: Journal of molecular structure. Theochem 1991-06, Vol.231, p.243-255
• Main Authors: Dolg, Michael, Stole, Hermann, Preuss, Heinzwerner
• Format: Article
• Language: English
• ISSN: 0166-1280; 1872-7999
• DOI: 10.1016/0166-1280(91)85223-T

SCF and CISD calculations have been performed for eight low-lying Λ S coupled states of CeO using nonrelativistic and quasirelativistic (one-component) energy-adjusted ab initio Pseudopotentials. The inclusion of spin-orbit coupling by means of energy-adjusted ab initio spin-orbit operators for Ce and limited quasirelativistic (two-component) CI calculations in the many-electron basis of the Λ S states leads to estimates for the molecular constants of sixteen low-lying Ω levels of which fourteen are known experimentally; the derived theoretical values for the 3Φ 2 ground state ( R e = 1.827 Å, D 0 = 7.24 eV, Ω e = 837 cm −1) are in good agreement with the corresponding experimental data ( R e = 1.820 Å, D 0 = 8.18 eV, Δ G 1 2 = 824 cm −1).