Аннотации:
We have performed high-accuracy quantum mechanical calculations for the three lowest S states of the
beryllium ion 9Be+ . The nonrelativistic part of the calculations was done with the variational approach and
explicitly included the nuclear motion i.e., the finite-nuclear-mass approach . The nonrelativistic wave functions
were expanded in terms of explicitly correlated Gaussian functions. These nonrelativistic functions were
subsequently used to calculate the leading 2 relativistic corrections =1/c and the 3 and 4 QED quantum
electrodynamics corrections. In the 4 QED correction we only accounted for its dominant component
typically contributing about 80% of the correction. With those the present results are the most accurate ever
obtained for 9Be+. They also agree with the experimentally measured transitions within less than 0.1 cm−1