Model core potentials for the lanthanides

Abstract

Model core potential (MCP) parameters and valence basis sets are determined for the lanthanides La through Lu. The 46 (1s–4d) electrons are replaced by the MCP and the 5s, 5p, 4f, 5d, and 6s are treated explicitly as valence electrons. The major relativistic effects at the level of Gowan and Griffin's quasi-relativistic Hartree–Fock method (QRHF) are incorporated into the MCPs. The valence orbitals thus obtained have inner nodal structure. The MCP is tested for various states of Pr, Pr +, Pr 2 + and Pr 3 + at the SCF level, and it is confirmed that the MCP determined for neutral atom works very well even for Pr 3 +. The CASSCF and SDCI calculations are performed for the ground state ( 3Φ) of CeO. The spectroscopic constants given by the SDCI including Davidson's correction ( r e=1.816 Å, ω e=866 cm − 1, and D e=7.89 eV) are in good agreement with the experimental values ( r e=1.820 Å, ω e=862 cm − 1, and D 0=8.18 eV).