ABINITIO PSEUDOPOTENTIAL STUDY OF EUROPIUM MONOXIDE EUO - 8-SIGMA- GROUND-STATE AND 8-SIGMA- 1ST EXCITED-STATE

Ab initio SCF and CISD calculations using nonrelativistic and quasirelativistic energy adjusted pseudopotentials and corresponding spin-orbit operators for Eu have been performed for the 8Σ- ground state and the 8Σ- first excited state of EuO. At the highest level of approximation the derived theoretical spectroscopic constants for the ground state (Re≈1.919 Å, D0=3.87 eV, ωe=702 cm-1) are in good agreement with corresponding available experimental data (Re≈1.89 Å, D0=4.92 eV, ωe=672 Large differential relativistic and correlation effects are found in the dissociation energy of the ground state and in the term energy of the first excited state, whereas bond lengths and vibrational frequencies are only slightly affected. © 1990.