A combination of quasirelativistic pseudopotential and ligand field calculations for lanthanoid compounds

SummaryImproved energy-adjusted quasirelativistic pseudopotentials for lanthanoid atoms with fixed valency are presented and tested in molecular calculations for CeO, CeF, EuO, GdO, YbO, and YbF. The pseudopotential calculations treat the lanthanoid 4f shell as part of the core and yield accurate estimates for average bond lengths, vibrational frequencies and dissociation energies of all states belonging to a superconfiguration. Information for each individual state of the considered superconfiguration may be obtained from subsequent ligand field model calculations. The results of this combined pseudo-potential and ligand field approach (PPLFT) are compared to more accurate calculations with ab initio pseudopotentials that include the lanthanoid 4f orbitals explicitly in the valence shell and to available experimental data.

[1]  H. Stoll,et al.  Ab initio pseudopotential study of europium monoxide EuO: 8Σ− Ground state and 8Σ− first excited state , 1990 .

[2]  P. Knowles,et al.  An efficient method for the evaluation of coupling coefficients in configuration interaction calculations , 1988 .

[3]  H. Stoll,et al.  Ab initio pseudopotential study of Yb and YbO , 1992 .

[4]  H. Stoll,et al.  Ab initio pseudopotential study of YbH and YbF , 1992 .

[5]  H. Stoll,et al.  Ab initio pseudopotential study of the 9Σ− and 7Σ− states of GdO , 1990 .

[6]  Michael Dolg,et al.  Energy-adjusted pseudopotentials for the rare earth elements , 1989 .

[7]  M. Pélissier,et al.  One‐center expansion for pseudopotential matrix elements , 1988 .

[8]  R. F. Barrow,et al.  Electronic states of the CeO molecule: absorption, emission, and laser spectroscopy , 1983 .

[9]  Ernest R. Davidson,et al.  Configuration interaction calculations on the nitrogen molecule , 1974 .

[10]  N. Rösch,et al.  Intermediate neglect of differential overlap spectroscopic studies on lanthanide complexes , 1992 .

[11]  W. J. Childs,et al.  Doppler-free laser spectroscopy of CeF and observation of hyperfine structure , 1991 .

[12]  J. Simons,et al.  The Hartree-Fock Method for Atoms , 1979 .

[13]  Michael Dolg,et al.  Energy‐adjusted ab initio pseudopotentials for the rare earth elements , 1989 .

[14]  R. Field.  Diatomic Molecule Electronic Structure beyond Simple Molecular Constants , 1982 .

[15]  J. P. Malrieu,et al.  Iterative perturbation calculations of ground and excited state energies from multiconfigurational zeroth‐order wavefunctions , 1973 .

[16]  H. Preuss,et al.  THE LOW-LYING ELECTRONIC STATES OF CERIUM MONOXIDE CEO : AB INITIO CALCULATIONS USING ENERGY-ADJUSTED PSEUDOPOTENTIALS AND SPIN-ORBIT OPERATORS , 1991 .

[17]  P. Knowles,et al.  An efficient internally contracted multiconfiguration–reference configuration interaction method , 1988 .

[18]  T. H. Dunning.  Gaussian Basis Functions for Use in Molecular Calculations. III. Contraction of (10s6p) Atomic Basis Sets for the First‐Row Atoms , 1970 .

[19]  H. Stoll,et al.  Pseudopotential study of the rare earth monohydrides, monoxides and monofluorides , 1989 .