Perturbation theory in calculations of atomic energy levels

On the basis of the field form of perturbation theory energy levels of atomic systems with numbers of electrons up to 10 are calculated. Configurations 1s 2 2s n1 2p n2 (n 1 =0-2, n 2 =0-6) are considered. The coefficients Delta E 1 , Delta E 2 in the energy expansion by powers of 1/Z E=E 0 Z 2 + Delta E 1 Z+ Delta E 2 + Delta E 3 Z / 1 ... are calculated. Hartree-Fock energies are also represented in the form of a Z-expansion, and the coefficients Delta E 1 HF , Delta E 2 HF , Delta E 3 HF of this expansion are computed. These calculations allow us to represent the correlation energy in the form of a Z-expansion.