Recent Advances in ab initio time—dependent Hartree-Fock theory and their applications to predict nonlinear optical properties of semiconductor nanoclusters

1999 ◽  
Vol 579 ◽  
Author(s):  
Shashi P. Karna ◽  
Prakashan P. Korambath
Keyword(s):  
Ab Initio ◽  
Nonlinear Optical ◽  
Time Dependent ◽  
Basis Set ◽  
Order Effects ◽  
Hartree Fock ◽  
Nlo Property ◽  
Nlo Materials ◽  
A Charge ◽  
Hf Calculations

ABSTRACTRecent advancements in ab initio time-dependent Hartree-Fock (TDHF) theory have made it a technique of choice for modeling nanoscale nonlinear optical (NLO) materials from first-principles. We have used this method to study structure-NLO property relationships of GaN, GaP and GaAs clusters. The geometry of the clusters used in the study was optimized by ab initio Hartree Fock (HF) calculations with the use of even tempered Gaussian (ETG) basis set. The clusters used in this study are of the type Gam Xn (M = 1,3,4,7 and n = 1,3,4,7) where X=N, P, and As. The GamXn clusters are in a charge neutral (q = 0) state for m = n and in appropriately charged state for m ∦ n. The magnitude of the calculated (hyper)polarizabilities appears to strongly depend on the composition of the cluster. For the same composition of heteroatoms, the hyperpolarizability depends on the size as well as the geometry of the cluster. The cluster size-dependence of calculated (hyper)polarizabilities is more pronounced for the first-hyperpolarizability. β than for the polarizability, α The calculated β(–ωμ,ωl,ω2) corresponding to various second order effects shows the following trend β(–2ω; ω,ω) > β(–ω; 0, ω) >β(0;0,0).

Nonlinear optical properties of novel thiophene derivatives: Experimental and ab initio time‐dependent coupled perturbed Hartree–Fock studies

1993 ◽  
Vol 99 (12) ◽  
pp. 9984-9993 ◽  
Author(s):  
Shashi P. Karna ◽  
Yue Zhang ◽  
Marek Samoc ◽  
P. N. Prasad ◽  
Bruce A. Reinhardt ◽  
...  
Keyword(s):  
Optical Properties ◽  
Ab Initio ◽  
Nonlinear Optical ◽  
Nonlinear Optical Properties ◽  
Time Dependent ◽  
Hartree Fock ◽  
Thiophene Derivatives

Theoretical investigation on the geometric, spectroscopic, nonlinear optical parameter, and frontier molecular orbital of 1,3-bis(4-methoxyphenyl)prop-2-en-1-one by DFT/ab initio calculations

2013 ◽  
Vol 91 (12) ◽  
pp. 1225-1232 ◽  
Author(s):  
Xiao-Hong Li ◽  
Rui-Zhou Zhang ◽  
Xian-Zhou Zhang
Keyword(s):  
Ab Initio ◽  
Title Compound ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Optical Parameter ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Chemical Hardness ◽  
Hartree Fock ◽  
The Difference

Quantum chemical calculations of energies, geometries, and vibrational wavenumbers of 1,3-bis(4-methoxyphenyl)prop-2-en-1-one (C17H16O3) in the ground state were carried out by the using ab initio Hartree−Fock and density functional theory (DFT/B3LYP) methods with the 6-311++G** basis set. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. Theoretical vibrational spectra of the title compound were interpreted by means of potential energies distributions. The theoretical spectrograms for IR spectra of the title compound have been constructed. The analysis of natural bond orbitals shows that the intramolecular hyperconjugative interactions are formed by the orbital overlap between π*(C–C) and π(C–C) bond orbitals, which results in intramolecular charge transfer causing stabilization of the system. The predicted nonlinear optical properties of the title compound are much larger than those of urea. In addition, the analysis of frontier molecular orbitals shows that the title compound has good stability and high chemical hardness.

scholarly journals Theoretical and experimental comparative studies of nonlinear optical properties for selected melaminium compounds

2010 ◽  
Vol 8 (6) ◽  
pp. 1192-1202 ◽  
Author(s):  
Marek Drozd ◽  
Mariusz Marchewka
Keyword(s):  
Optical Properties ◽  
Acetic Acid ◽  
Nonlinear Optical ◽  
Time Dependent ◽  
X Ray ◽  
Hartree Fock ◽  
Optical Applications ◽  
Experimental Values ◽  
Nonlinear Optical Applications ◽  
Theoretical Results

AbstractThe bis(melaminium) sulphate dihydrate, 2,4,6-triamine-1,3,5-triazin-1,3-ium tartrate monohydrate, 2,4,6-triamine-1,3,5-triazin-1-ium hydrogenphthalate, 2,4,6-triamine-1,3,5-triazin-1-ium acetate acetic acid solvate monohydrate, 2,4,6-triamine-1,3,5-triazin-1-ium bis(selenate) trihydrate, melaminium diperchlorate hydrate, melaminium bis(trichloroacetate) monohydrate and melaminium bis(4-hydroxybenzenesulphonate) dihydrate were discovered recently as perspective materials for nonlinear optical applications. On the basis of X-ray structures for eight melaminium compounds the time dependent Hartree Fock (TDHF) method was used for calculation of the polarizability, and first and second hyperpolarizability. Detailed directional studies of calculated hyperpolarizability for all investigated melaminium compounds are shown. The theoretical results are compared with experimental values of β.

Sign in / Sign up

Export Citation Format

Share Document