The nonlinear coefficients, n4, of the time-dependent refractive index for argon are calculated in the non-resonant optical regime. Second-order polynomial fitting of DC-Kerr, γ((2))(-ω; ω, 0, 0), electric field induced second harmonic generation (ESHG), γ((2))(-2ω; ω, ω, 0), and static second-order hyperpolarizability, γ((2))(0; 0, 0, 0), is performed using an auxiliary electric field approach...

Several DFT functionals have been carried out to study the first hyperpolarizabilities βHRS of push-pull polyene as a function basis sets, electron correlation, size, frequency dispersion and geometry. These calculations confirm huge effects Møller– Plesset (MP2) results reproduces values hyperpolarizability obtained with reference CCSD(T) level. Among density functional theory exchange- correl...

Polyacetylene (PA) polymers -(-CH=CH-), lead to large second hyperpolarizabilities (y) that increase with N. For small N the increase is quite rapid, eventually saturating (becoming linear in N) for N > N& Both experimental and theoretical attempts have been made to estimate N,Y,,. In 1994 this led to two Science papers, one obtaining NA, = 20 (semiempirical theory) and the other obtaining N,,,...