[en] Some specific features of the 4f wavefunction collapse in the rare-earth elements and its effect on all nf electrons with n > 4 are considered and the results of the investigation used in Dirac-Fock self-consistent field calculations for lanthanum (6s²nfsub(5/2) and europium (6s²4f⁶sub(5/2)nfsub(7/2)) with n = 4,5 and 6. The exchange interaction is shown to play an important role in the formation of 'collapsed' and 'blown' states of these atoms with n = 4. A calculation has been made of the contribution to the total energy of an atom coming from the lanthanum 4fsub(5/2) and europium 4fsub(7/2) electrons in the 'collapsed' and 'blown' states of these atoms. The europium nfsub(7/2) electrons with n = 5 and n = 6 are shown to be localised in the outer well of the effective potential, their one-electron parameters being close to those of the 5f and 6f electrons in the Coulomb field, respectively. At the same time in lanthanum with n = 5 and n = 6, the nfsub(5/2) electrons can be found with a high probability in either of the effective potential wells. (author)