Molecular Structures and Relativistic Effective Core Potentials for the X5Σ- of PuO Molecule

Three kinds of Relativistic Effective Core Potentials (RECP) with B3LYP, MP2 and HF methods have been used to work out the structures for the ground state of PuO molecule, whose equilibrium nuclear distances, disassociation energies, spectral constants and harmonic frequencies have been obtained. The ab initio energy data of PuO have been least-square-fitted to the Murrell-Sorbie potential energy function, from which the corresponding spectral constants, the second, third and forth forcec on stants have been derived. The results indicate that SDDRECP with B3LYP method could give the best calculations in agreement with the experimental results. The charge populations, spindensities and dipole moments of PuO molecule to the different RECP sand calculation levels have also been tabled out.