We present an approach for obtaining a molecular orbital picture of the first dipole hyperpolarizability (β) from correlated many-body electronic structure methods. Ab initio calculations β rely on quadratic response theory, which recasts sum-over-all-states expression into closed-form by calculating handful first- and second-order states; resonantly enhanced β, damped theory is used. These sta...

Quantitative structure-activity relationship (QSAR) models were useful in understanding how chemical structure relates to the toxicology of chemicals. In present study, we report quantum molecular descriptors using conductor like screening model (COs) area, linear polarizability, first and second order hyperpolarizability for modelling nitro substituent on benzene ring. All performed semi-empir...

Fourier transform Raman and infrared spectra of 4-hydroxy-2,6-dimethyl pyrimidine (HDMP) were recorded and interpreted by comparison with respective theoretical spectra calculated using HF and B3LYP methods. The HDMP equilibrium geometry with Cs symmetry, harmonic vibrational frequencies, infrared and Raman intensities were determined using HF/6-311G and B3LYP/6-311G level of theories. The band...

The static linear and nonlinear optical properties of (ZnO)N clusters of N= 2-12 are studied using finite field approach within the framework of density functional theory. Most of these clusters feature ring or cage structures in the specific size range, differing much from the wurtzite structure of bulk ZnO. The low-lying isomers with various structures possess remarkably different properties....

Modulating the second-order nonlinear optical susceptibility (χ(2)) of materials at the nanoscale represents an ongoing technological challenge for a variety of integrated frequency conversion and nonlinear nanophotonic applications. Here we exploit the large hyperpolarizability of intermolecular charge transfer states, naturally aligned at an organic semiconductor donor-acceptor (DA) interface...

The static and dynamic first hyperpolarizabilities for a series of substituted metallabenzene-based nonlinear optical (NLO) chromophores were determined by time-dependent density functional theory (TDDFT). The electronic excitation contributions to the first hyperpolarizability are rationalized in terms of the two-level model. The effects on the hyperpolarizabilities of (a) the metal center (Os...

A detailed analysis of the selected DFT functionals for the calculations of interaction-induced dipole moment, polarizability and first-order hyperpolarizability has been carried out. The hydrogen-bonded model chains consisting of HF, H(2)CO and H(3)N molecules have been chosen as a case study. The calculations of the components of the static electric properties using the diffuse Dunning's basi...