Comparison of EHMO and SCF Results on Polyacetylene

Chapter 15 Molecular Orbital Theory of Periodic Systems 

We have seen that Peierls distortion produces a band gap at the Fermi level in polyacetylene. Another type of change we can consider is replacement of one kind of atom in the unit cell with another. While this is not a modification that the polymer can make spontaneously, it is a way for us to predict what sort of changes in band sttucture would result if substitutional relatives of polyacetylene were synthesized. 

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