Ab initio QED calculations in diatomic quasimolecules
We present a theoretical approach for ab initio calculations of the one-loop QED corrections to energy levels of heavy diatomic quasimolecules. This approach is based on the partial-wave expansion of the molecular wave and Green functions in the basis of monopole solutions, written in spherical coordinates. By using so generated molecular functions we employed the existing atomic-physics techniques to evaluate the self-energy and vacuum-polarization corrections. In order to illustrate the application of our method, we perform detailed calculations of the Dirac energy and QED corrections for the 1$\sigma_g$ ground state of homonuclear U$_2^{183+}$ as well as heteronuclear U-Pb$^{173+}$ and Bi-Au$^{161+}$ quasimolecules.