A correlated study of linear optical absorption in tetracene and pentacene

In this paper, we report large-scale configuration interaction (CI) calculations of linear optical absorption spectra of tetracene and pentacene. For the purpose, we used Pariser–Parr–Pople (P–P–P) model Hamiltonian and quadruple-CI (QCI) and multi-reference single–double CI (MRSDCI) approaches. The role of Coulomb parameters used in P–P–P Hamiltonian was also examined by considering standard parameters as well as screened set of parameters. Results are presented both for the long- and the short-axis-polarized components of the spectra and wave functions of various excited states have also been analysed.