Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Jones formalism

First, the ratio is constructed from the spectra at each rotation angle a or tilt angle / with the help of the linear correlation analysis (K. Fahmy, personal communication) A(a)/A(o=0) [A(/ )/A(/ =0)]. The ratio of each transition moment as a function of the angle a or can thus be obtained. This theoretical function can be calculated with the help of the Jones Formalism (4) and this function is necessary for fitting the ratios at o=90 and 0=90 degrees to obtain the dichroic ratio Ax/Ay and Ay/Az. Finally the normalized absorption axes can be determined. [Pg.1080]

Crystals with high dichroism — Jones Formalism. [Pg.1081]

This setup allows the determination of the unknown ellipsometric angles and can be operated in various modes. Each optical component modifies the state of polarization. Since any state of polarization can be represented by a complex Jones vector consisting of two columns, the effect of each optical components is described by a complex 2x2 matrix. The Jones formalism provides an elegant means for a quantitative description [4]. [Pg.7]

Jones R O 1987 Molecular calculations with the density functional formalism Advances in Chemicai Physics vol LXVIl, ed K P Lawley (New York Wiley-Interscience) pp 413-37... [Pg.2198]

Here Tq are coordinates in a reference volume Vq and r = potential energy of Ar crystals has been computed [288] as well as lattice constants, thermal expansion coefficients, and isotope effects in other Lennard-Jones solids. In Fig. 4 we show the kinetic and potential energy of an Ar crystal in the canonical ensemble versus temperature for different values of P we note that in the classical hmit (P = 1) the low temperature specific heat does not decrease to zero however, with increasing P values the quantum limit is approached. In Fig. 5 the isotope effect on the lattice constant (at / = 0) in a Lennard-Jones system with parameters suitable for Ne atoms is presented, and a comparison with experimental data is made. Please note that in a classical system no isotope effect can be observed, x "" and the deviations between simulations and experiments are mainly caused by non-optimized potential parameters. [Pg.95]

Jones, R. O., Gunnarsson, 1989, The Density Functional Formalism, its Applications and Prospects , Rev. Mod. [Pg.292]

The basic formalism of the X-dynamics method has taken various forms in its application to problems of interest. In an early prototype calculation to assess umbrella sampling in chemical coordinates, the X-dynamics method was used to evaluate the relative free energy of hydration for a set of small molecules which included both nonpolar (C2H6,) and polar (CH3OH, CH3SH, and CH3CN) solutes.1 By assigning a separate X variable to the Lennard-Jones and Coulomb interactions, a linear partition of the potential part of the hybrid Hamiltonian was constructed... [Pg.216]

Another longtime subject of debate in C7H6 chemistry is the role of cy-cloheptatrienylidcne (4a). As already mentioned, 4a was initially viewed as the product of ring expansion of la. Attempts were also made to generate 4a directly. Upon pyrolysis or photolysis of the sodium salt of tropone tosylhy-drazone (5), W.M. Jones and co-workers isolated heptafulvalene, the formal product of dimerization of 4a (Scheme 8).21 In the presence of alkenes, decomposition of 5 or dehydrohalogenation of halocycloheptatrienes afforded mainly spirocyclopropane products, presumably formed by addition of 4a to the alkene (Scheme 8).22... [Pg.210]

Logic91] See, for example, Jones, C. B., et al. 1991. MURAL A Formal Development Support System. New York Springer. [Pg.734]

As far as the polymerisation of heterocyclic monomers is concerned, the situation is qualitatively similar, but quantitatively different. As a model for the active species in oxonium polymerisations, Jones and Plesch [10] took Et30+PF6 and found its K in methylene dichloride at 0 °C to be 8.3 x 10"6 M however, in the presence of an excess of diethyl ether it was approximately doubled, to about 1.7 x 10 5 M. This effect was shown to be due to solvation of the cation by the ether. Therefore, in a polymerising solution of a cyclic ether or formal in methylene dichloride or similar solvents, in which the oxonium ion is solvated by monomer, the ion-pair dissociation equilibrium takes the form... [Pg.419]

Diamond (1966) has applied a filtering procedure in the refinement of protein structures, in which poorly determined linear combinations are not varied. In charge density analysis, the principal component analysis has been tested in a refinement of theoretical structure factors on diborane, B2H6, with a formalism including both one-center and two-center overlap terms (Jones et al. 1972). Not unexpectedly, it was found that the sum of the populations of the 2s and spherically averaged 2p shells on the boron atoms constitutes a well-determined eigenparameter, while the difference is very poorly determined. Correlation between one- and two-center terms was also evident in the analysis. [Pg.79]

The previous basic observations have suggested to adopt a closure that allows us to interpolate continuously between two existing theories. In this framework, the famous HNC-SMSA(HMSA) closure [22] has been proposed for the Lennard-Jones fluid. It interpolates between HNC and SMSA. The HMSA has strong theoretical basis since it can be derived from Percus functional expansion formalism and its bridge function expresses as a functional of the remormalized indirect correlation function y (r) = y(r) — Pmi,r(/") so that... [Pg.23]

In the general case, when s-polarized light is converted into p-polarized light and/or vice versa, the standard SE approach is not adequate, because the off-diagonal elements of the reflection matrix r in the Jones matrix formalism are nonzero [114]. Generalized SE must be applied, for instance, to wurtzite-structure ZnO thin films, for which the c-axis is not parallel to the sample normal, i.e., (1120) ZnO thin films on (1102) sapphire [43,71]. Choosing a Cartesian coordinate system relative to the incident (Aj) and reflected plane waves ( > ), as shown in Fig. 3.4, the change of polarization upon reflection can be described by [117,120]... [Pg.89]

A mode coupling theory is recently developed [135] which goes beyond the time-dependent density functional theory method. In this theory a projection operator formalism is used to derive an expression for the coupling vertex projecting the fluctuating transition frequency onto the subspace spanned by the product of the solvent self-density and solvent collective density modes. The theory has been applied to the case of nonpolar solvation dynamics of dense Lennard-Jones fluid. Also it has been extended to the case of solvation dynamics of the LJ fluid in the supercritical state [135],... [Pg.314]

Recently, Garth Jones (UNSW) and his co-workers have described a semi-classical molecular dynamics (MD) model, which incorporates the trajectory surface hopping (TSH) method, that shows promise in investigating a number of important problems concerning the effects of molecular vibrations on the dynamics of ET reactions, including formally symmetry-forbidden ones. Essentially,... [Pg.75]


See other pages where Jones formalism is mentioned: [Pg.37]    [Pg.36]    [Pg.206]    [Pg.662]    [Pg.163]    [Pg.37]    [Pg.36]    [Pg.206]    [Pg.662]    [Pg.163]    [Pg.561]    [Pg.29]    [Pg.916]    [Pg.13]    [Pg.337]    [Pg.179]    [Pg.86]    [Pg.3]    [Pg.24]    [Pg.26]    [Pg.103]    [Pg.128]    [Pg.29]    [Pg.47]    [Pg.46]    [Pg.257]    [Pg.760]    [Pg.674]    [Pg.460]    [Pg.577]    [Pg.69]    [Pg.279]    [Pg.53]    [Pg.213]    [Pg.292]    [Pg.191]    [Pg.196]    [Pg.225]    [Pg.7]   
See also in sourсe #XX -- [ Pg.89 ]

See also in sourсe #XX -- [ Pg.163 ]




SEARCH



Jones matrix formalism

Model Using Jones Matrix Formalism

© 2024 chempedia.info