TWO-ELECTRON WAVEFUNCTIONS FOR THE GROUND AND EXCITED STATES OF ALKALI NEGATIVE IONS

Author Institution: Laboratoire de Physique Mol\'eculaire et des Collisions, Technop\^ole 2000In order to propose a long range model including ionic covalent interaction in the determination of highly excited slate potential curves of alkali dimers, a model has been developped to compute the energies and wave functions of the ground state and various excited states of alkali negative ions. In case of the ground State (Magnier el al. J. Phys. B: At. Mol. Phys. 32 5639 (1999)), a two-electron correlated wave function has been suggested in the framework of a model potential method in which core polarization effects have been included. This method based on the formalism developped with success for $H^{-}$ (Le Sech, J. Phys. B: At. Mol. Phys. 30 L47 (1997)), gives very good results for all alkali negative ions since the ground state energy is reproduced with an accuracy of $10^{-6} a.u.(\approx 0.2 cm^{-1})$. For the excited states, energies and wave functions have been determined through interaction configuration calculations involving highly excited Slater type orbitals. Comparison with available experimental and theoretical data is satisfying