Lithium , isoelectronic series

Calculations of IIq(O) are very sensitive to the basis set. The venerable Clementi-Roetti wavefunctions [234], often considered to be of Hartree-Fock quality, get the sign of IIq(O) wrong for the sihcon atom. Purely numerical, basis-set-free, calculations [232,235] have been performed to establish Hartree-Fock limits for the MacLaurin expansion coefficients of IIo(p). The effects of electron correlation on IIo(O), and in a few cases IIq(O), have been examined for the helium atom [236], the hydride anion [236], the isoelectronic series of the lithium [237], beryllium [238], and neon [239] atoms, the second-period atoms from boron to fluorine [127], the atoms from helium to neon [240], and the neon and argon atoms [241]. Electron correlation has only moderate effects on IIo(O). 

They have additional two publications, which have the following titles FSGO study of the Gauss-type pseudopotential for the Lithium and Lithium(l-) and its isoelectronic series, ab initio molecular fragment calculations with pseudopotentials, calculation on Li2, LiH and BeH2, and Ab initio molecular fragment calculations with pseudopotentials model peptide studies . ... 

In our laboratory a series of laser-microwave studies has been performed on metastable and short-lived excited states of heliumlike Li. Singly ionized lithium, like all members of the two-electron He isoelectronic sequence, belongs to the fundamental systems in atomic physics. Many of its spectroscopic and quantum-mechanical characteristics have been calcu-... 

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