Bond alternation in infinite periodic polyacetylene: Dynamical treatment of the anharmonic potential

► The anharmonic Peierls vibration of infinite periodic polyacetylene is treated. ► The force at large displacement is estimated in two ways and via a DFT calculation. ► Anharmonic treatment results in ZPE above the barrier with a single maximum. ► The three estimation methods agree with each other and are not sensitive to the values of the parameters. ► The realistic CC bonding stiffness precludes bond alternation in this model olyacetylene.