Properties of negatively charged lithium ions and evaluation of the half-life of ${}^7$Be atom(s)

Bound state properties of the four-electron lithium ion Li${}^{-}$ in its ground $2^{2}S-$state and isotope-subsistuted ${}^6$Li${}^{-}$ and ${}^7$Li${}^{-}$ ions in their ground $2^{1}S-$state(s) are determined from the results of accurate, variational computations. Another closely related problem discussed in this study is accurate numerical evaluation of the half-life of the beryllium-7 isotope. This problem is of paramount importance for modern radiochemistry.