LAUSR

An algorithm for calculating the leading relativistic corrections for D states of atoms with an arbitrary number of electrons with all-electron explicitly correlated Gaussian functions is derived and tested in calculations for the helium and beryllium atoms. The finite-nuclear-mass approach used enables us to determine the isotopic shifts of the corrections. The results for interstate transitions for D states of the helium atom are compared with previous calculations. The results for the beryllium atom are compared with the experimental values, as these are high-accuracy calculations of D states of a four-electron atom performed with the inclusion of the leading relativistic corrections. The calculated and experimental values agree with each other within the experimental error bar.