Cavity volume

Fig. 5. Probabilities pn of observing n water-oxygen atoms in spherical cavity volumes v. Results from Monte Carlo simulations of SPC water are shown as symbols. The parabolas are predictions using the flat default model in Eq. (11). The center-to-center exclusion distance d (in nanometers) is noted next to the curves. The solute exclusion volume is defined by the distance d of closest approach of water-oxygen atoms to the center of the sphere. (Hummer et al., 1998a)... 

In the foregoing the description of microresonators was limited to the index guiding type. Resonators with the same functionality can be implemented in PBG structures5. In these cases, with the high index contrast used, the cavity volume is even more reduced resulting in FSRs of 10 - 100 nm. 

Figure 2. Left Family of softball" monomers 4-7. Different spacers between the centerpiece and the glycoluril binding sites permit assembly of dimers with cavity volumes between 186 A3 and 313 A3. Right Computer-minimized...

Determine the actual cavity volume and surface area within the Delaunay tetrahedra The overlap of the exclusion spheres with the relevant Delaunay tetrahedra is subtracted analytically, leaving only the actual cavity volume and surface area. This nontrivial calculation is from the multiple overlap of exclusion spheres, but a systematic method for carrying it out is available.70 71... 

Figure 12.3 Rigid and flexible molecular interaction field maps with the hydrogen probe in the active-site cavity for CYP2C9 and UCT2B7 enzymes. It is worth noting that, with flexible side chains, the overall cavity volume changes considerably. This demonstrates the important role played by MIF-flexibility calculations in enzyme-substrate recognition.

The study of solute-solvent and solvent-solvent interactions in mixed solvents has been gaining significance in recent years61-64, because of the increasing application of these solvents. Casassas and collaborators67 have used the Kamlet-Taft multiparametric equation for the correlation of dissociation constants of acids in 1, 4-dioxane-water mixtures. They found that when the main solvent is retained the property does not involve significant changes in the cavity volumes and, in those cases, the pK in binary solvents can be described by equation 8 ... 

F. M. Richards, Packing defects, cavities, volume fluctuations and access to the interior of proteins, Carlsberg Res. Commun. 44, 47-63 (1979). 

Now at minimum cavity volume (Vj j ) the gas will have its maximum pressure value. 

Values range from + 22 cm /mol for m-xylene to —27 cm /mol for 1-pentene. This depends on the relative magnitude of two large volume terms that make up Vg. One is the cavity volume, a positive term, and the other is the electrostriction of the solvent around the trapped electron. Whereas the electrostriction term varies considerably depending on the compressibility of the solvent, the cavity volume does not change much and the average value for the hydrocarbons is 96 cm /mol, corresponding to a cavity radius of 0.34 nm. 

Thus from pulse radiolysis, mobility measurements, and electron reaction studies, we have information on the absorption spectra, the cavity volume, and the energy of the trapped or solvated state. The nature of this state seems to be an electron that is localized in a cavity in the liquid. 

For certain liquids like cyclohexene [158], o-xylene, and m-xylene [159], the mobility increases with increasing pressure (see Fig. 11). These results provided the key to understand the two-state model of electron transport. In terms of the model, AFtr is positive for example, for o-xylene, AFtr is +21 cm /mol. Since electrostriction can only contribute a negative term, it follows that there must be a positive volume term which is the cavity volume, Fcav(e). The observed volume changes, AFtr, are the volume changes for reaction (23). These can be identified with the partial molar volume, V, of the trapped electron since the partial molar volume of the quasi-free electron, which does not perturb the liquid, is assumed to be zero. Then the partial molar volume is taken to be the sum of two terms, the cavity volume and the volume of electrostriction of the trapped electron ... 

Whether is positive or negative depends on the relative value of the two terms in Eq. (25). Ten hydrocarbons were studied and the cavity volume term was found to be rela-... 

Polymer Matrices. An excellent example of systems in which there is potentially a wide distribution of reaction cavity volumes and for which... 

The index m, representing the maximum sorption in the cavity, may he derived from considerations of the zeolitic cavity volume and molar volume of the sorhate, as m <. v/0. However Schirmer et al. (7 ) state that a maximum of 6 terms has been used in their work. 

T0 Standard state for temperature = 273.IK v Cavity volume = 776 cubic angstoms... 

---