In the coordination field calculation of rare-earth ions, the D-2 point group basis functions were classified and labeled according to the relation of the point group chain R(3)* superset of O* superset of D-4* superset of D-2*. The perturbation matrix elements of the coordination field for the rare-earth complexes in the dihedral field were systematically derived with the double-sphere coordination point-charge field (DSCPCF) model and the irreducible tensor operator method and the corresponding computer program DSF. D was compiled. The DSCPCF perturbation energy levels of Eu(phen)(2)(NO3)(3) and Eu(PU)(8)(NO3)(3) were calculated, and the fluorescence spectra were assigned. The calculated results agree with the observed.