H. Nobutoki, THEORETICAL-STUDIES ON QUASI-DIABATIC ELECTRONIC EFFECTS IN LITHIUM HEAVILY-DOPED POLYACETYLENE, JOURNAL OF PHYSICAL CHEMISTRY B, 101(20), 1997, pp. 3999-4003
A quasi-diabatic crystal orbital (CO) theory earlier developed has bee
n applied to lithium heavily-doped trans-polyacetylene (t-PA) to study
quasi-diabatic electronic effects in a metallic state. It has been sh
own that the quasi-diabatic electronic structure largely changes from
the adiabatic electronic structure. This change arises from the strong
interaction of the crystal momentum coupling between carbon pi and li
thium canonical COs. The coupling also leads to occurrence of a large
spin-density-wave (biradical character) in the quasi diabatic electron
ic state. The occurrence has been analyzed to be due to a large electr
on-electron repulsive interaction. The quasi-diabatic electronic struc
ture has been discussed with a focus on the electron-electron repulsio
n.