Nearest- neighbor characterized

This region has been divided into two subphases, L and S. The L phase differs from the L2 phase in the direction of tilt. Molecules tilt toward their nearest neighbors in L2 and toward next nearest neighbors in L (a smectic F phase). The S phase comprises the higher-ir and lower-T part of L2. This phase is characterized by smectic H or a tilted herringbone structure and there are two molecules (of different orientation) in the unit cell. Another phase having a different tilt direction, L, can appear between the L2 and L 2 phases. A new phase has been identified in the L 2 domain. It is probably a smectic L structure of different azimuthal tilt than L2 [185]. 

Especially for large values of Aw, there could be an additional entropy effect beyond that calculated in the last section which arises from the interaction of nearest neighbors. That is, reaction (8.A) might be characterized by both a AHp jj. and a ASp jj.. In this case Aw might be viewed as the pairwise contribution to a free energy ACpaj with... 

In the CHS model only nearest neighbors interact, and the interactions between amphiphiles in the simplest version of the model are neglected. In the case of the oil-water symmetry only two parameters characterize the interactions b is the strength of the water-water (oil-oil) interaction, and c describes the interaction between water (oil) and an amphiphile. The interaction between amphiphiles and ordinary molecules is proportional to a scalar product between the orientation of the amphiphile and the distance between the particles. In Ref. 15 the CHS model is generalized, and M orientations of amphiphiles uniformly distributed over the sphere are considered, with M oo. Every lattice site is occupied either by an oil, water, or surfactant particle in an orientation ujf, there are thus 2 + M microscopic states at every lattice site. The microscopic density of the state i is p.(r) = 1(0) if the site r is (is not) occupied by the state i. We denote the sum and the difference of microscopic oil and water densities by and 2 respectively and the density of surfactant at a point r and an orientation by p (r) = p r,U(). The microscopic densities assume the values = 1,0, = 1,0 and 2 = ill 0- In close-packing case the total density of surfactant ps(r) is related to by p = Ylf Pi = 1 - i i. The Hamiltonian of this model has the following form [15]... 

Some evolution types observed in our simulations are shown in Figs. 2-7. The simulations were performed for the same 2D alloy model as that used in Refs. , on a square lattice of 128x128 sites with periodic boundary conditions. The as-quenched distribution Ci(0) was characterized by its mean value c and small random fluctuations Sci = 0.01. The intersite atomic jumps were supposed to occur only between nearest neighbors and we used the reduced time variable t = <7,m-... 

The dielectric constant and refractive index parameters and different functions of them that describe the reactive field of solvent [45] are insufficient to characterize the solute-solvent interactions. For this reason, some empirical scales of solvent polarity based on either kinetic or spectroscopic measurements have been introduced [46,47]. The solvatochromic classification of solvents is based on spectroscopic measurements. The solvatochromic parameters refer to the properties of a molecule when its nearest neighbors are identical with itself, and they are average values for a number of select solutes and somewhat independent of solute identity. 

To treat the orientational structure of the monolayer formed by 02 molecules on a graphite surface, allowance must be made for the fact that an oxygen molecule is characterized not only by a nonzero magnetic moment but also by a record small quadrupole moment, so that dispersion interactions prevail over quadrupole interactions at intermolecular distances shorter than 10 A.79 In addition, the adsorbate lattice parameters give rise to very small minimum intermolecular distances, a 3.3 A, the parameter b 8.1 A markedly exceeding the values a. That is why, it is sufficient to consider only the nearest-neighbor interactions in a... 

The nearest-neighbor interaction coefficient, W = EAA + Ebb 2EAB, and the temperature together characterize the molar free energy of mixing ... 

All real crystals have atoms which occupy external surface sites and which do not possess the correct number of nearest neighbors as a consequence, Thus, a surface is a scat of energy and is characterized by surface tension. Furthermore, internal surfaces exist, grain boundaries and twin boundaries across which atoms are incorrectly positioned. In a crystal of reasonable size—say 1 cubic centimeter, these two-dimensional defects, called surface defects, contain only about 1 atom in 106, a rather small fraction. Even so, surfaces are important attributes of solids. 

We consider a simple cubic lattice with a coordination number 2 = 6. For an incompressible polymer solution, each lattice site is occupied by a solvent molecule or by a segment of polymer chain. The attraction interactions between the nearest-neighbor sites are characterized by a reduced exchange energy = fi( pp + ss 2eps) between a segment p and a solvent s, where is the attractive energy of an i—j pair. 

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