INTERACTION OF 2 SOLITONS ON 2 TRANS-POLYACETYLENE CHAINS

We have studied the interaction of two solitons on two trans-polyacetylene chains in the framework of the molecular orbital theory employing the spin-restricted Hartree-Fock (RHF) and the unrestricted Hartree-Fock (UHF) methodologies for π-electrons. We discuss the energetical stability for the cases of a singlet pair of neutral solitons and a pair of oppositely charged solitons, each soliton existing and interacting on the two chains. We have found the former to be energetically more stable and that a transition from the former to the latter would take place upon photoexcitation. The decrease in the intensity of the electron spin resonance signal upon photoexcitation can be explained by this transition. © 1990.