On the calculation of electric dipole strengths of 4f→4f transitions in lanthanide complexes

Electric dipole strengths calculated with the combined static coupling (SC)/dynamic coupling (DC) intensity model for 4f → 4f transitions in lanthanide complexes contain SC/DC cross-term (“interference”) contributions which may add to or subtract front the purely static and dynamic contributions. Calculations for europium (III) complexes show that cross- terms cannot be neglected in characterizing 4f→4f intensities.