Abinitioself-consistent field molecular orbital calculations have been performed to obtain the intramolecular rotational potential energy surface forcis-transoidalpolyacetylene with simultaneous rotations about two successive single bonds. The results indicate the possibility of existence of a “superhelix” instead of a tight 2*3/1 helix. Using the energy surface obtained, Monte Carlo calculations have been done to obtain the probabilities of the existence of various conformations of this polymer.