Isospin method for complex electronic configurations

Advanced multiconfiguration methods for complex atoms: I. Energies and wave functions

“…It has been intensively used for testing the extension of the HF code to the f N shell for general occupation numbers [92]. It is worthwhile to note that in the checking process, "accidental" zeros characterizing the Hartree-Fock solution of Lanthanides in their ground state and appearing in 4f → nf Brillouin's matrix elements were discovered and remain unexplained, even after exploring the use of an isospin basis [118,119].…”

Reduced Coefficients of Fractional Parentage and Matrix Elements of the Tensor W(kqkj) in jj-Coupling

“…The use of different phases in the formula (8) has often led to confusion and inconsistencies in the derivation of proper formulae for complex spectra. We are using the same phase γ as in the work of Kaniauskas et al [41], i.e.,…”

Self-consistent field method in various approximations: 'forgotten ideas'

“…Con® gurations n 1 l N 1 n 2 l N 2 may obey some additional symmetry property, described by the so-called isospin basis [39]. In this basis two electrons belonging to different shells with the same l are interpreted as two states of a particle, having an additional degree of freedom in the isospin space.…”

“…The relevant operator T …1 † is the irreducible tensor in the additional isospin space. In this way we o er a new e cient version of Racah algebra for such electronic con® gurations, again covering both the non-relativisti c and relativistic cases [38,39].…”