The method reported by Luo and Huang (J. Phys.: Condens. Matter 1993, 5, 9411) for analysing the optical data of Cr3+ complexes, which uses only a coupling to one single vibrational mode is discussed. Taking as a guide the case of the CrF63- complex it is pointed out firstly that the frequency omega used in the method has no direct physical meaning, being smaller than those associated with A1g and Eg modes observed in optical spectra, and secondly that the assumed relation between 10Dq and the Stokes shift ES is in general not true as it is only valid for the partial contribution of the A1g mode to ES. Despite these facts it is also explained that no unreasonable band-width values can be predicted provided that the fitted values of the Huang-Rhys factor and the frequency reproduce the experimental Stokes shift. In conclusion the proposed method of Luo and Huang is shown to be not conceptually right, giving rise to a worse description than that achieved through the coupling to the two A1g and Eg modes of the CrF63$complex.