Essential single bonds application

In other words, fixed double bonds are always accompanied by fixed single bonds. From this viewpoint we may say that fixed single bonds are the fiindamental feature of essentially disconnected systems. The simple reasoning of the above proof is applicable to other essentially disconnected systems than single coronoids as well. It has been applied to benzenoids by Chen, Cyvin SJ and Cyvin (1990). 

Since these double-base proplnts consist essentially of a single phase which bears the total load in any application of force, their mechanical property behavior is significantly different from composite proplnts. In the latter formulations, the hydrocarbon binder comprises only about 14% of the composite structure, the remainder being solid particles. Under stress, the binder of these proplnts bears a proportionately higher load than that in the single phase double-base proplnts. At small strain levels, these proplnts behave in a linear viscoelastic manner where the solids reinforce the binder. As strain increases, the bond between the oxidizer and binder breaks down... 

The bond strength measured or estimated at a constant temperature or at a specified facet of single-crystal planes are, of cause, important factors in the discussion of electrocatalysis. But, if they are obtained under different conditions from the practical ones, the conclusion might not be correct. The author believes that the general understanding on the size effect still needs further experimental and theoretical studies. Particularly careful attention should be paid to the operation temperature, the coagulation of nanoparticles during the experiment, or the territory. Of course, evaluation on the stability of such small particles is essential in the practical application. 

What functions shall we use for the single-electron MOs We could try the exact MOs for shown in Fignre 6.2. However, these exact MOs are not described by simple eqnations, and they are inconvenient for applications. Therefore, we introdnce the LCAO method to construct approximate MOs directly from the Hartree AOs for the atoms in the molecule, guided by molecular symmetry and chemical intnition. The essential new feature compared with the atomic case is that the (multicenter) approximate MOs are spread around all the nuclei in the molecnle, so the electron density is de-localized over the entire molecule. The approximate MOs therefore differ considerably from the (single-center) AOs nsed in Section 5.2. Constructing the approximate MOs and nsing them in qnalitative descriptions of bonding are the core objectives of this section. 

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