Atom generalized

Racah parameters The parameters used to express quantitatively the inter-electronic repulsion between the various energy levels of an atom. Generally expressed as B and C. The ratios between B in a compound and B in the free ion give a measure of the nephelauxetic effect. ... 

Most studies indicate that air velocity has a profound influence on mean droplet size in twin-fluid atomizers. Generally, the droplet size is inversely proportional to the atomizing air velocity. However, the relative velocity between the Hquid and air stream is more important than the absolute air velocity. 

Values for tt-electron density on nitrogen atoms generally indicate the position of electrophilic attack, e.g. at the 3-position of 1,2,3-thiadiazoles. 

Finally, the parametrization of the van der Waals part of the QM-MM interaction must be considered. This applies to all QM-MM implementations irrespective of the quantum method being employed. From Eq. (9) it can be seen that each quantum atom needs to have two Lennard-Jones parameters associated with it in order to have a van der Walls interaction with classical atoms. Generally, there are two approaches to this problem. The first is to derive a set of parameters, e, and G, for each common atom type and then to use this standard set for any study that requires a QM-MM study. This is the most common aproach, and the derived Lennard-Jones parameters for the quantum atoms are simply the parameters found in the MM force field for the analogous atom types. For example, a study that employed a QM-MM method implemented in the program CHARMM [48] would use the appropriate Lennard-Jones parameters of the CHARMM force field [52] for the atoms in the quantum region. 

These definitions are clear, but they do not apply to the vast majority of real molecules in which the bonds are neither purely ionic nor purely covalent. Lewis recognized that a pair of electrons is generally not shared equally between two electrons because the atoms generally have different powers of attracting electrons, that is, they have different electronegativities, giving charges to both atoms. Such bonds are considered to have some covalent character and some ionic character and are known as polar bonds. 

Numerous Zind anions are formed by selenium and tellurium, with some of the more prominent species being Se 2 (where n 2, 4, 5, 6, 7, 9, or 11). The species with n = 11 contains two rings that have five and six members that are joined by a selenium atom. Those with smaller numbers of selenium atoms generally consist of zigzag chains. Tellurium forms an extensive series of polyanions that are present in such species as NaTe (n = 1 to 4). One tellurium anion contains the Hg4Te124 ion, but other species such as [( lg2Tes) 2 are also known, such as the Te122 anion that is present in some cases where the cation is a +1 metal. 

Atomization generally refers to a process in which a bulk liquid is disintegrated into small drops or droplets by internal and/or external forces as a result of the interaction between the liquid (dispersed phase) and surrounding medium (continuous phase). The term dispersed phase represents the liquid to be atomized and the atomized drops/droplets, whereas the term continuous phase refers to the medium in which the atomization occurs or by which a liquid is atomized. The disintegration or breakup occurs when the disruptive forces exceed the liquid surface tension force. The consolidating... 

The accurate spatial location of these atoms generally needs a sophisticated approach, for example, the study of a complete deuterated set of isotopic derivatives in microwave spectroscopy or the use of neutron diffraction techniques. We shall see below that a set of CNDO/2 calculations combined with suitable experiments (microwave spectroscopy and/or electron diffraction) may help to solve the geometrical and conformational analysis of compounds containing many hydrogen atoms. 

Withdrawal of electrons from orbitals symmetric between hydrogen atoms (generally inductive effects) should lead to a positive change in the coupling constants. ... 

Sketch diagrams of an ether and an alcohol with the same number of carbon atoms. Generally speaking, would you expect an ether or an alcohol to be more soluble in water Explain your reasoning. 

The coupling occurs at the carbon atoms (generally via a-a links) which are the most reactive to addition and substitution reactions ... 

For most commercial polymers, carbon and silicon are the two backbone building blocks, and they routinely form chains of like atoms. Generally three types of covalent bonds are associated with carbon in the production of commercial vinyl polymers, as shown in Fig. 2.5 the single, double, and triple carbon-to-carbon bonds. 

The reactivity of allylchlorosilanes for the alkylation of ferrocene varies depending upon the substituents on the silicon atom. Generally, the reactivity increases as the number of alkyl groups on the silicon of allylsilanes increases." Allyl(dialkyl)-chlorosilanes react with ferrocene in the presence of HfCU under mild reaction... 

The centrally located atom in a coordination entity to which other atoms or group of atoms (generally referred to as ligands) binds. 

Because natural sulfur has eight sulfur atoms contained within each molecule, the number of sulfur atoms generally varies between 1 and 8. 

Equation 5 is often used to decribe the interaction between the incoming ion and the target atoms. The interaction between two target atoms generally occurs at low energy where the Thomas-Fermi potential overestimates the interaction. Under this situation a Born-Mayer potential is more appropriate , i.e. ... 

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