Two different approaches to the determination of the dependence of the electronic transition moment on the internuclear distance, Me(R), are considered. It is shown that Me(R) dependences obtained by ab initio and semi-empirical methods take into account electronic-vibrational interactions in a various manner. In semi-empiral methods these interactions are take into account to a greater degree, than in non-empirical quantum-mechanical methods which do not include nonadiabatic corrections. A system of concepts, which allows to unite the information obtained in two different, mutually complementing ways, is considered in the paper.