In this paper we present a detailed computational study of the electronic
structure and optical properties of triply-bonded hydrocarbons with linear, and
graphyne substructures, with the aim of identifying their potential in
opto-electronic device applications. For the purpose, we employed a correlated
electron methodology based upon the Pariser-Parr-Pople model Hamiltonian,
coupled with the configuration interaction (CI) approach, and studied
structures containing up to 42 carbon atoms. Our calculations, based upon
large-scale CI expansions, reveal that the linear structures have intense
optical absorption at the HOMO-LUMO gap, while the graphyne ones have those at
higher energies. Thus, the opto-electronic properties depend on the topology of
the {graphyne substructures, suggesting that they can be tuned by means of
structural modifications. Our results are in very good agreement with the
available experimental data.Comment: main text 29 pages + 4 figures + 1 TOC graphic (included), supporting
information 21 page
