Theoretical investigation of second hyperpolarizability of trans-polyacetylene: Comparison between experimental and theoretical results for small oligomers

Abstract

The development of new conductive polymers nowadays is one of the most important technological areas in materials design. Computational investigation of desired properties in conductive polymers could save financial resources and time, but it is important to choose the methodology that produces good results comparing to experimental results. To verify the prediction of second hyperpolarizability (γ) in oligomers of Trans-Polyacetylene (TPA) by theoretical calculations, a series of semi-empirical, Hartree-Fock (HF), and Density Functional Theory (DFT) calculations were performed and analysed through linear fitting statistical analysis to investigate the accuracy of such theoretical predictions in comparison to the experimental ones. The results showed that HF and DFT methodologies do not describe γ with good accuracy, but the use of diffuse and polarizability functions in HF methodology provided better results than 3-21G and 6-31G functions. It was concluded that RM1 methodology better agrees with γ experimental results for TPA oligomers, and linear fitting statistical analysis is a useful tool to compare experimental and theoretical results.

Impact of doping on the optoelectronic, electronic and nonlinear optical properties and on the reactivity of photochromic polymers containing styrylquinoline fragments: Hartree-Fock and DFT study

“…Thus, the first order ( ), second order ( ) and third order ( ) electric susceptibility tensors are defined by [30] , [31] where , and are the polarizability and first and second hyperpolarizability tensor components and V the volume of our monomer. Atomic unit were translated into SI units and electrostatic units using conversion factors available in the literature [32] , [33] .…”

Density functional theory calculations for electronic, optoelectronic and thermodynamic properties of dibenzothiophene metal complexes

“…For the calculation of optoelectronic properties of the molecules, the conversion factors required to convert atomic units to SI units: 1 Debye=3.336×10 −30 Cm (Coulomb meter), 1 a. u. of α=1.64878×10 −41 C 2 m 3 J −1 , 1 a. u. of β=8.6393×10 −33 esu=3.206361×10 −53 C 3 m 3 J −2 , and 1 a.u. of γ=6.23597×10 −65 C 4 m 4 J −3 [27,28]. Also, pressure and temperature are set to 1atm and 298.15 K, respectively for all the thermodynamic property calculations.…”

RM1 Semiempirical Model: Chemistry, Pharmaceutical Research, Molecular Biology and Materials Science

“…A study that also focused on non-linear optics properties was performed by de Andrade et al 314 This time, the studied molecular systems were small oligomers of trans-polyacetylene. Semiempirical methods, DFT and Hartree-Fock model chemistries were used to calculate the second hyperpolarizability (γ) for these molecular systems.…”