Virtual Vibrational Spectrometer For Sp(2) Carbon Clusters. 1. Polycyclic Benzenoid-Fused Hydrocarbons

A virtual vibrational spectrometer HF-Spectrodyn, based on efficient computational codes and exploring both restricted and unrestricted Hartree-Fock approximations, is proposed to perform computational vibrational spectroscopy of large sp(2) carbon clusters. The computational device allows obtaining one-quantum harmonic spectra of IR absorption and Raman scattering of closed-shell and open-shell molecules. The spectrometer facilities are manifested for the sp(2) hydrocarbons on the example of polyacenes (naphthalene and pentacene) and polycyclic benzenoid-fused compounds (coronene as well as (5,5) and (9,9) periacenes). The observed trends disclose a new spectrometric approach for the consideration of vibrational spectra of the molecules in terms of standard valence bonds subjected to particular structural and atomic-content affects.