The excited-state polarization model is modified by taking into account the different pyroelectric processes in polar crystals and the difference between the mean emission frequency ν2 and the electronic transition frequency ν3 which results from the stokes shift in the radiative trasition. According to this model, the results for the dipole moment charge △μfrom different specimens of crystal LiNbO3 :Cr3+ used by different authors are identical within experimental errors: △μis about 3 Debye, and almost indepeudent of temperature in the whole experimental temperature region 50—300 K.