Fig. 5: Integral cross sections.
From: Unexpected steric hindrance failure in the gas phase F− + (CH3)3CI SN2 reaction

Cross sections as a function of collision energy for the E2 and SN2 reactions on the FI-NN PES and those for the SN2 reaction on the modified PES. A repulsive potential between F− and β-H in the vicinity of the E2 transition state of the FI-NN PES was added in the modified PES, which blocks the E2 pathway, but nothing is changed for SN2 as presented above.