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Atoms chemical bond strengths

In addition, the Mulliken population analysis [2] is common in the field of molecular orbital calculations, and the nature of the chemical bond between atoms has been treated well by using a standard concept of covalent or ionic bond. However, with this analysis it is still difficult to compare quantitatively the chemical bond strength among a variety of materials. To solve this problem, the chemical bond should be estimated quantitatively in an energy scale. [Pg.146]

The bond energy is a direct measure of chemical bond strength. Its value is determined by the work necessary to destruct the bond between the atoms of molecular structure (or the gain of energy in the formation process of this structure from atoms). If the molecule contains two or more similar bonds, the break-off energy of this bond differs from its average energy (by all bonds). [Pg.13]

The semi-empirical CNDO/2 method has been applied64 to an analysis of the electronic structure and conformation of disulphur decafluoride. The results, in good agreement with the available experimental data, enable the calculation of the electronic terms which determine the shape of the potential surface and a discussion of the electronic non-equivalence of the axial and equatorial fluorine atoms, the chemical bond strength, and the anomalous S—S bond length in the S2F10 molecule. [Pg.413]

Phonon velocity is constant and is the speed of sound for acoustic phonons. The only temperature dependence comes from the heat capacity. Since at low temperature, photons and phonons behave very similarly, the energy density of phonons follows the Stefan-Boltzmann relation oT lvs, where o is the Stefan-Boltzmann constant for phonons. Hence, the heat capacity follows as C T3 since it is the temperature derivative of the energy density. However, this T3 behavior prevails only below the Debye temperature which is defined as 0B = h( DlkB. The Debye temperature is a fictitious temperature which is characteristic of the material since it involves the upper cutoff frequency ooD which is related to the chemical bond strength and the mass of the atoms. The temperature range below the Debye temperature can be thought as the quantum requirement for phonons, whereas above the Debye temperature the heat capacity follows the classical Dulong-Petit law, C = 3t)/cb [2,4] where T is the number density of atoms. The thermal conductivity well below the Debye temperature shows the T3 behavior and is often called the Casimir limit. [Pg.631]

According to q.(2.31) only the correction due to double counting of the electron- electron interactions on the same atom has to be explicitly accounted for. Within the Extended-Huckel method this correction is usually ignored. As we will sec later, depending on orbital occupation the contribution to the chemical bond strength... [Pg.32]

Changing the hybridization from spz to sp2 increases the s character of the chemical bond. This enhances the attractive contribution of the chemical bond strength and shortens the Si-Si bonds. The surface Si atom is pulled into the plane formed by its nearest-neighbor surface atoms. This changes sp to sp2 hybridization see Fig.(2.29). The p orbital of the unsaturated Si atom perpendicular to the surface can now become stabilized by overlap with the Si-Si bonds between the next-neighbor Si atom. Such hybridization has been observed for quartz by... [Pg.70]

Predict trends in the vibrational constant based on atomic mass and chemical bond strength. [Pg.355]

Sets of Atoms Differing in Mass or Chemical Bond Strength... [Pg.203]

Heat resistance is iafluenced by both the type and extent of cure. The greater the strength of the chemical bonds ia the cross-link, the better is the compound s heat resistance. Peroxide cure systems, which result ia carbon—carbon bonds, result ia a range of sulfur cross-links varyiag from 1 to > 30 sulfur atoms per cross-link, and heat resistance improves as the number of more thermally stable short cross-links predominates. This is an important factor ia designing the desired cure system. [Pg.236]


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Atom bonding

Atomic bonding

Atoms bonds

Atoms chemical bonds

Bond strength

Bond strength, chemical

Bonding strength

Bonds atomic

Chemical atom

Chemical bonding strength

Sets of Atoms Differing in Mass or Chemical Bond Strength

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