The electronic structures of undimerized and dimerized trans and cis polyacetylene have been calculated by means of the first principles Linear-Muffin-Tin-Orbital method. The pi electronic states, which are supposed to be particular important to many of the physical properties of polyacetylene, are investigated in detail. In this connection it is examined to which extent model Hamiltonians of the type used Su, Schrieffer, and Heeger can be applied.
 

Physica Scripta, T13 306-13, 1986.