title: Bound states of the barium atom by the hyperspherical approach.
abstract: We present a nonadiabatic hyperspherical calculation of the highly excited and low lying doubly excited states of the barium atom using effective potentials for the two optically active electrons' interactions. Within the hyperspherical adiabatic approach the investigation of the spectra is performed with potential curves and nonadiabatic couplings of a unique radial variable, which allows clear identification of the states. The convergence of energy is obtained within well established bound limits, and the precision is comparable to accurate configuration interaction calculations. A very good agreement with experimental results is obtained with only few nonadiabatic couplings.
authors.affiliation: Instituto de Química de Araraquara, Universidade Estadual Paulista-UNESP, Caixa Postal 355, 14801-970 Araraquara, São Paulo, Brazil. maccebim@posgrad.iq.unesp.br
authors.forename: M A
authors.initials: MA
authors.lastname: Cebim
authors.forename: J J
authors.initials: JJ
authors.lastname: De Groote