Nonlinear optical properties calculation

Kamiya M, Sekino H, Tsuneda T, Hirao K (2005) Nonlinear optical property calculations by the long-range-corrected coupled-perturbed Kohn-Sham method. J Chem Phys 122(23) 234111... 

Polarizabilities and hyperpolarizabilities have been calculated with semi-empirical, ah initio, and DFT methods. The general conclusion from these studies is that a high level of theory is necessary to correctly predict nonlinear optical properties. 

Ah initio methods are applicable to the widest variety of property calculations. Many typical organic molecules can now be modeled with ah initio methods, such as Flartree-Fock, density functional theory, and Moller Plesset perturbation theory. Organic molecule calculations are made easier by the fact that most organic molecules have singlet spin ground states. Organics are the systems for which sophisticated properties, such as NMR chemical shifts and nonlinear optical properties, can be calculated most accurately. 

DHF (Dirac -Hartree-Fock) relativistic ah initio method DHF (derivative Hartree-Fock) a means for calculating nonlinear optical properties... 

There have been very few measurements made on the physical properties of Tg derivatives, their relative greater difficulty of preparation when compared with the Tg analogs has meant little interest in their properties. However, TglOSiMeslg has been found to show photoluminescence in the blue region of the spectrum, third-order nonlinear optical properties for TgMeg have been modeled, and electronic properties for and TgMeg have been calculated. 

Recently, Romero and Andrews [1], and Lipinski [2] have shown that the calculated sum over states of a one-electron nonlinear optical property of a molecular system must vanish provided that the wave function employed satisfies the Hellmann-Feynman theorem. This statement applies, in particular, to the electric dipole polarizahility and, as a consequence, there must exist systems which exhibit, most prohahly in excited states, a negative polarizability. Several examples of atomic and molecular systems with negative polarizability can be found in Refs. [3-8]. In search for such systems we study the state of... 

In this paper, we make use of molecular modelling techniques, particularly the AMI semiempirical molecular orbital method, to study the intermolecular interactions that are important for determining the manner in which crystal formation takes place. We are particularly inter ested in compounds that can potentially exhibit nonlinear optical properties. The calculational techniques are directed towards providing insight into the manner in which the desired nonlinear optical properties can be op timized in the macromolecular crystal state.(1)... 

The comparison of the two isomeric nitroanilines is that of two similar molecules, one (para) crystallizes in a centrosymmetric, the other (meta) in a non-centro-symmetric manner. (6) Thus, only the meta exhibits nonlinear optical properties. Dimers of these (and several other) nitroanilines were calculated using AMI, and found to be in good agreement with the experimentally determined structures. (7) Here we focus on how these dimers can interact with additional molecules. 

Bishop s attention turned to accurate calculations of electrical and magnetic properties, especially those of importance in nonlinear optics. Since most experiments in this field measure ratios, not absolute values, it is necessary to have a calculated value. Universally, Bishop s helium nonlinear optical properties are used. In the same field, he was the first to seriously investigate the effects of electric fields on vibrational motions, with a much-quoted paper.65 His theory and formulation has now been added to two widely used computational packages HONDO and SPECTROS. He has also derived a rigorous formula to account for the frequency dependence (dispersion) in nonlinear optical properties.66 He used this theory to demonstrate that the anomalous dispersion in neon, found experimentally, is an artifact of the measurements. 

In contrast to the computations of the preceding section we directly calculate the expectation value of the CC dipole operator (finally linearized with respect to the external field) applying the classical path approximation for nuclear dynamics. Such a direct calculation of the dipole operator expectation value becomes of particular interest when focusing on ultrafast nonlinear optical properties (transient absorption, photon echo signal, etc.). 

For the description of the linear and nonlinear optical properties of metallotetrapyrroles, TDDFT methods have proven [133-148] to be an excellent alternative to conventional highly correlated ab initio methods, such as SAC-CI, STEOM-CC, and CASPT2, for which these systems still represent a severe computational challenge, especially when transition metals, lanthanides or actinides are involved. The few highly correlated ab initio calculations dealing with the excited state properties of metallotetrapyrroles that have appeared to date only concern magnesium and zinc porphyrins and porphyrazines [149-151]. Application of TDDFT methods to the electronic spectroscopy of a variety of metallotetrapyrroles, including homoleptic and heteroleptic sandwiches, will be illustrated in this section. 

TDDFT methods have also been applied successfully to the description of the linear and nonlinear optical properties of heteroleptic sandwich complexes. The optical spectrum and the hyperpolarizability of Zr(OEP)(OEPz,) for which large first hyperpolarizabilities, /JSHG (SHG=second-harmonic generation) were measured in an electric field induced second-harmonic generation (EFISH) experiment [182], have been investigated by TDDFT methods [134]. The excitation energies and oscillator strengths calculated... 

Jensen, L. and Duijnen P. Th. van, The Discrete Solvent Reaction Field model A Quantum me-chanics/Molecular mechanics model for calculating nonlinear optical properties of molecules in the condensed phase., in Atoms, molecules and clusters in electric fields. Theoretical approaches to the calculation of electric polarizability, G. Maroulis, Editor. 2006, Imperial College Press London, p. 1-43. 

E. Westin, Calculations of Linear and Nonlinear Optical Properties of Ionic Crystal Surfaces and Fullerenes Thesis Chalmers University of Technology, Goteborg, 1995. 

Semi-empirical ZINDO SOS (sum over states) and ab initio quadratic response function (DDRPA) calculations on a series of D-A-substituted 7t-conjugated chromophores based on styryl benzothiazoles were used to aid in the design of dyes with high nonlinear optical properties <2004PCP495>. 

CALCULATIONS OF NONLINEAR OPTICAL PROPERTIES FOR THE SOLID STATE... 

With few exceptions, a useful nonlinear optical material will be in the solid phase for example, a single crystal or a poled polymer embedded in a film. Ironically, the quantum chemical calculations of nonlinear optical properties have for the most part been concerned with a single microscopic species. Much has been learned in this way about appropriate molecular construction, but the ultimate goal must be to investigate the nonlinear optical (NLO) properties in the solid phase. 

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