Study of the importance of relativistic, correlation, and relaxation effects on ionization energy of atoms by a relativistic and correlated local density method

The effect of relativistic corrections, correlation, and relaxation on the ionization energy of inner and outer orbitals of light and heavy atoms has been studied using the "fully" correlated relativistic local density method - called the RCΞ method. The validity of Koopmans' theorem is also discussed in this paper. © 1995 American Institute of Physics.