title: Polymer Optical Constants from Long-Range Corrected DFT Calculations.
abstract: A methodology to calculate refractive indices of plastics based on the Lorentz-Lorenz equation has been proposed. The polarizability of the nonconjugated polymer repeat units is predicted using the long-range corrected functionals. The end effect corrections in repeat unit models are essential to achieve accuracy similar to that observed for molecular liquids (ca. 1% in mean absolute deviation). The functionals with 100% Hartree-Fock (HF) exchange in the long-range limit perform best for aromatic and other hydrogen-deficient compounds; the Coulomb-attenuated hybrid exchange-correlation functional (CAM-B3LYP) performs very well for hydrogen-rich (usually, fully saturated) compounds. Exceptionally good agreement is observed for the sets of wavelength-dependent refractive index data for polystyrene, poly(methyl methacrylate), and for poly(perfluoro-4-vinyloxy-1-butene) (CYTOP), for which the root-mean-square deviations are 0.004, 0.002, and 0.004, respectively.
authors.affiliation: R&D Center, Mitsui Chemicals, Inc. , 580-32 Nagaura, Sodegaura, 299-0265, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Maekawa
authors.affiliation: R&D Center, Mitsui Chemicals, Inc. , 580-32 Nagaura, Sodegaura, 299-0265, Japan.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Moorthi