OPTIMIZED RELATIVISTIC MANY-BODY PERTURBATION THEORY IN CALCULATIONS OF ATOMIC SPECTRAL AND RADIATION CHARACTERISTICS: Eu ATOM

The new formalism of the relativistic gauge-invariant perturbation theory (RMBPT-ODF) with optimized Dirac-Fock approximation and a generalized energy approach is applied to study energy, radiation, spectroscopic characteristics group heavy atomic systems, in particular, levels transition probabilities oscillator strengths transitions 4f7(8S)6s2 8S7/2 4f7(8S)6s6p 8P5/2,7.2,9.2, 4f7(8S)6s7p 8P5/2,7\2, 4f7(8S)6s8p 8P9/2,7\2 spectrum europium atom Eu I. It shown that required formalism, comparison standard non-optimized Hartree-Fock methods, allows obtaining more accurate data both on energies amplitudes radiative transitions, which due use zero ODF approximation, fairly complete effective account complex many-body exchange-correlation effects. contribution polarization core reaches 30% value strength; calibration-invariant radiation width fractions percent, contrast all existing methods modern spectroscopy, for 5-50%.