AbstractThe consideration of transfer processes of an electron from ligand to the trivalent lanthanide ion allows to obtain theeffective dipole‐moment operator containing the terms having complicated tensor structure. Using the second quantization technique as well as the canonical‐transformation method permit to write the expression for the electric‐dipole (4f‐4f)‐transition probabilities in a form, which is convenient for the interpretation of the experimental data. The expression for the transition probabilities contains traditional Ω2, Ω4, and Ω6 parameters as well as four additional D2, D4, L2, and L4 ones being due to the complicated tensorial structure of the electric‐dipole moment operator. The microscopic analysis carried out for the Er3+ ion in LaF3, single crystal shows that one can neglect the terms with L2, and L4 parameters. Using the new parametrization scheme containing five parameters (Ω2, Ω4, Ω6, D2, and D4,) the intensity spectroscopic properties of Pr3+ ions in Bi4Ge3O12, single crystal are non‐contradictorily described, where the hypersensitive inter‐manifold 3II4 → 3F2 transition is taken into account. On the basis of this parametrization scheme the best description of the experimental data as a whole as well as of the hypersensitive inter‐manifold 4I15/12 → 2H11/2, 4G11/2 transitions of Er3+ ions in Y3Al5O12, Lu3AI5O12, and BaYb2F8 single crystals are also obtained.