On the Electric Dipole (hyper)polarizability of Difluorodiacetylene (F-C≡C-C≡C-F)

We report static dipole polarizability and hyperpolarizability values difluoroacetylene obtained from finite-field density functional theory and conventional ab initio calculations with especially designed flexible basis sets of Gaussian-type functions. Our results show that electron correlation has a small effect on the dipole polarizability but a strong one on the hyperpolarizability. The widely used B3LYP method yields molecular properties fairly close to the ab initio ones. The effect of the fluorination on the molecular properties is quite obvious at the self-consistent field level of theory: α (FCCCCF) α (HCCCCF) α (HCCCCH) and γ (FCCCCF) γ (HCCCCF) γ (HCCCCH).