Singlet and triplet bound state spectra in the four-electron Be-like atomic systems

Maria Belen Ruiz, Federico Latorre, Alexei M. Frolov

A large number of bound singlet and triplet states in the four-electron Be-atom and Be-like ions B${}^{+}$, C${}^{2+}$, F${}^{5+}$ and Mg${}^{8+}$ are determined to milli-Hartree numerical a…