Shell charge

The two bonding maxima and the two nonbonding maxima in the valence shell charge concentration of the sulfur atom in SCF have an approximately tetrahedral atfangement just like the two bonding domains and the two nonbonding domains of the VSEPR model. As we shall see, this correspondence is found for many other molecules, and so it seems reasonable... 

Figure 7.6 Contour maps of L for H2O, (left in the molecular plane right, perpendicular to the molecular plane), NH3 (in a symmetry plane through N and one H), and CH4 (in a symmetry plane through C and two H s). The maxima in the valence shell charge concentration are indicated by the dots.

The localization of the valence shell electrons of the central atom into pairs that is the basis of the VSEPR model can be clearly seen in the contour map of L for a plane through the carbon atom and two Cl ligands for the CC14 molecule given in Figure 8.8. There is a maximum in the valence shell charge concentration of both carbon and chlorine along each... 

Renovation and Salvage. Ammunition which has deteriorated to such a stage that replacement of the fuzes, boosters, shell charges or propelling charges is necessary,... 

It is indicated, that PETN-wax compns for use in detonators, boosters and pressed shell charges are competitive with RDX-wax compns. Fragmentation tests of waxed PETN containing 10 to 13% wax is recommended for direct comparison with Compn A... 

Sand tests indicate Torpex to be 98 to 99% as brisant as RDX and 122% as brisant as TNT. As judged by plate dent test values, cast Torpex is 120% as brisant as TNT. Fragmentation tests of shell charges indicate it to be 126% as brisant as TNT and, therefore, inferior to Composition B in this respect. The detonation rate of cast Torpex (1 diam charge, d 1.81g/cc = 7495 m/sec) is 110% that of TNT. Trauzl Pb block tests and its heat of expln (see above) indicate Torpex to be 162% as powerful as TNT, with the BalPend test showing a superiority of. 34%... 

The brisance of Tritonal is 100% of that of TNT, as judged by sand test values, but plate dent tests indicate it to be only 93% and fragmentation tests of shell charges show it to be but 91% as brisant as TNT. The rate of detonation of cast Tritonal is approx 97% that of cast TNT. The heat of expln of Tritonal is 60% greater than that of TNT, but Tritonal is only 124% as powerful, as measured by the ballistic pendulum test. When tested for blast effect, Tritonal has relative peak pressure and positive impulse values of 113 and 118%, respectively, of those for TNT... 

Fig. 15 Fitting result of the first pre-Rietveld analysis of Sc2 C66 based on the homogeneous spherical shell charge density model for the fullerene cage. The section MEM charge density of Sc2 C66 based on the pre-Rietveld analysis is inserted. The contour lines are drawn from 0.0 to 3.0 e A-3 with 0.3 e A-3 intervals...

The postulates of VSEPR theory are consistent with the partitioning of electron density according to Bader s atoms-in-molecules method [173], in which the electron pairs return as the valence shell charge concentration. 

The magnitudes of both the core and shell charges are fixed in this model. The polarization thus occurs via relative displacement of the core... 

---