Refractions atoms

Atomic Refractivities Atomic refractivities may be attributed by virtue of ... 

Atom-type Atomic refractivity Atom type Atomic refractivity... 

The descriptor uses readily calculable physicochemical properties from the topological structure. The descriptors used in this study were atomic weight, hydropho-bicity, molecular refractivity, atomic charge, polar surface area, hydrogen bond acceptors, and hydrogen bond donors. The authors note that Martin et al. [32] applied a similar approach for the design of diverse combinatorial libraries. 

LEED angles must be corrected for refraction by the surface potential barrier [73]. Also, the intensity of a diffraction spot is temperature dependent because of the vibration of the surface atoms. As an approximation. 

The next step towards increasing the accuracy in estimating molecular properties is to use different contributions for atoms in different hybridi2ation states. This simple extension is sufficient to reproduce mean molecular polarizabilities to within 1-3 % of the experimental value. The estimation of mean molecular polarizabilities from atomic refractions has a long history, dating back to around 1911 [7], Miller and Sav-chik were the first to propose a method that considered atom hybridization in which each atom is characterized by its state of atomic hybridization [8]. They derived a formula for calculating these contributions on the basis of a theoretical interpretation of variational perturbation results and on the basis of molecular orbital theory. 

Here, k is a factor which converts to units (kcal/mol in this case where the distances are in A and the polarisabilities in A ). G, and Gj are constants chosen to reproduce the well depths for like-with-like interactions. The atomic polarisability values are obtained from an examination of appropriate molecular experimental data (such as measurements of molar refractivity). 

The values for the D sodium line of the atomic and structural constants and of the bond refractions, as determined by the author, are collected in Tables XI,2A and XI,2B respectively. 

From the atomic and group refractions in Table 5.19, the molar refraction is computed as follows ... 

The dielectric constant is a measure of the ease with which charged species in a material can be displaced to form dipoles. There are four primary mechanisms of polarization in glasses (13) electronic, atomic, orientational, and interfacial polarization. Electronic polarization arises from the displacement of electron clouds and is important at optical (ultraviolet) frequencies. At optical frequencies, the dielectric constant of a glass is related to the refractive index k =. Atomic polarization occurs at infrared frequencies and involves the displacement of positive and negative ions. 

The real component of the neutron refractive index 8 is related to the wavelength X of the incident neutrons, the neutron scatterir length (a measme of the extent to which neutrons interact with different nuclei), the mass density and the atomic... 

In this list, p is the mass density, X b is the sum of scattering lengths of the atoms con rising the molecule, 8 is the real part of the refractive index, Gq is the critical angle, and is the critical neutron momentum. 

Br. CHa. CHa. CHa. CH(NHa). CH(CHa). CHa. CHjBr HBr. which on treatment with dilute alkali gives di-heliotridane (II). As the latter contains two asymmetric carbon atoms, two diastereoisomeric racemates might be produced in this reaction but only one was formed. It had density and refractive index in general agreement with those recorded for Z-heliotridane, as were also the melting points of characteristic derivatives. Density Df °0-902, refractive index wf, 1-4638 (<. with Adams and Rogers,3i Df ° 0-935, iijf° 1-4641), picrate, m.p. 234-6° (literature 232-6°), picrolonate, m.p. 162-3°, aurichloride, m.p. 200-1° (Konovalova and Orekhov give for these two constants 152-3° and 199-200° respectively). 

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