Ionization potentials of internal conversion electrons for the superheavy elements 112, 114, 116, and 118

K-shell $(1s)$ and L-shell $(2s)$ ionization potentials for the superheavy elements with $Z=112,$ 114, 116, and 118 are predicted to an accuracy of a few 10 eV using Dirac-Hartree-Fock theory and taking into account quantum electrodynamic and nuclear-size effects. The data obtained are for any number of electrons and can be used in the future in theoretical and experimental studies of these elements involving K-electron conversion spectroscopy.