The utilization of correlation crystal field models for the analysis o
f experimental spectra is developing for lanthanides. These models are
useful to improve the fits for the few levels which are badly fitted
by the standard model. For actinides the crystal field simulation is u
sually less satisfactory and the addition of the correlation crystal f
ield is expected to bring some improvements. It has already been utili
zed for Np3+ in LaCl3. In the present work, the spectroscopic data of
some U4+-doped compounds are re-analysed in terms of a crystal model c
ontaining one- and two-electron operators. In the examined compounds t
he actinide ion is coordinated to three types of ligands: oxygen, chlo
rine and bromine. The re-analysed data are those of uranium-doped ThSi
O4, ZrSiO4, ThCl4, alpha-ThBr4 and beta-ThBr4 and UCl4. Adding four to
eight two-electron operators (depending on the compound) results in d
ividing by 2.4 the r.m.s. deviation between the experimental and calcu
lated energy level positions with respect to the standard one-particle
parametrization. Systematic trends are sought in order to help the an
alysis for forthcoming compounds.