We also performed NEGF-DFT calculations for the high conductance state of PPP, which involves the formation of an Au-C covalent bond. Our results indicate that there is a tenfold difference in computed transmission values between the high and low conductance states of PPP (Figure ), in accordance with our experimentally observed STM-BJ results. The differences between experimental and computed transmission values could arise due to the semi-local exchange-correlation functional (PBE) used in our calculations, which tends to underestimate the HOMO-LUMO gap between the electrodes and molecule. In addition, the electron transmission calculations are carried out at zero applied bias. The experimental STM-BJ results indicate an increase in conductance with an increase in bias. Overall, NEGF-DFT calculations combined with MD simulations support the hypothesis that the low conductance state arises due to non-covalent intermolecular interactions and the high conductance state involves the formation of a robust Au-C covalent linkage.