Periodic Hartree-Fock and density functional theory calculations for Li-doped polyacetylene chains

We have performed periodic restricted Hartree-Fock/6-31G(**) and B3LYP/6-31G(**) density functional theory calculations on Li-doped trans-polyacetylene at various dopant concentrations, using C2mH2mLi2 unit cells (m=7-14). Except for maintaining P (1) over bar rod symmetry the geometry was completely optimized for both uniform and nonuniform doping structures. In addition to geometry we obtain atomic charges, along with soliton formation and dopant binding energies, as well as band structures and densities of states. A thorough analysis of the band structure and density of states, as a function of dopant concentration, is presented. We also characterize the complex nature of the binding interaction between Li and the polyacetylene chain. (c) 2006 American Institute of Physics.