[en] Shown is the application possibility of an approximated semi-empirical method of total neglect of differential overlapping (TNDO) for calculation of momentum distribution of annihilating electron-positron pairs and investigation of relative momentum distribution of electrons of wide molecule class. The used scheme for positron wave function calculation and the TNDO method ensure a satisfactory agreement of theory and experement for nonpolar molecules. The application possibility of the method for proving positron solvation in polar media is discussed