Polymer Optical Constants from Long-Range Corrected DFT Calculations

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• 作者：Shintaro Maekawa ; Krzysztof Moorthi
• 刊名：Journal of Physical Chemistry B
• 出版年：2016
• 出版时间：March 10, 2016
• 年：2016
• 卷：120
• 期：9
• 页码：2507-2516
• 全文大小：460K
• ISSN：1520-5207

文摘

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.