Analysis is being carried out in the paper of a possibility of obtaining lasing effect on the transitions between the repulsive terms (with no potential wells) of diatomic molecules comprising the flying apart fragments. In our analysis we used model potential curves of the upper and lower lasing terms of such molecules. It was assumed that such a molecule can be formed due to collisions of a B atom in its ground state with an A atom excited by electrons to an upper level with the energy E2. Assuming the concentration of A atoms to be equilibrium at the electron temperature Te, we have found the ratio Te/E2 and concentrations of the atoms A and B in their ground states that favor obtaining the lasing effect on the transition between the repulsive terms of molecules comprising the flying apart fragments.