Nearest neighbor site

The stacking order of the lithium interlayers is aa (a Li-C6 -Li-C6 -Li chain exists along the c-axis) [84, 85], In LiC6 the lithium is distributed in-plane in such a manner that the occupation of the nearest-neighbor sites is avoided (Fig. 5b). 

In LGCA models, time and space are discrete this means that the model system is defined on a lattice and the state of the automaton is only defined at regular points in time with separation St. The distance between nearest-neighbor sites in the lattice is denoted by 5/. At discrete times, particles with mass m are situated at the lattice sites with b possible velocities ch where i e 1, 2,. .., b. The set c can be chosen in many different ways, although they are restricted by the constraint that... 

Note also that the choice of what the move X- X from one phase space point to the next means microscopically depends on the type of problem that one wishes to study e.g., for a simulation of surface difiusion in the framework of the lattice gas model (see section 4.2), this move may mean a hop of a randomly chosen adatom to a randomly chosen nearest neighbor site (and W = 0 it this latter site is already taken). 

The existence of multiple peaks for molecular desorption has been attributed to lateral interactions among adsorbed species 62-64). As discussed previously, adsorption onto the surface lattice may occur preferentially in next nearest neighbor sites to form p(2 x 2) structures. Even at low coverages, attractive forces may cause adatoms to occupy next nearest neighbor positions, so that clusters of adsorbate form which have local twofold periodicity 65) with respect to the surface. Such effects are entirely consistent with the perturbations of the surface electronic wave functions due to adsorption 66-68) which show that these binding sites represent the... 

The Seebeck data of Fig. 5 provide information (1) on the thermal excitation of mobile electrons to the FeA sites, particularly above T, (2) the change in spin degeneracy at Tj, and (3) the influence of a AH < kT on the accessibility of nearest-neighbor sites. 

The fast-forward protocol can be used to assist an incomplete STIRAP population transfer via control of the time dependences of the phases of the fields. As a first example, we reconsider transfer of particles between sites of a linear lattice. In this example, the hopping rates, which connect nearest neighbor sites, are the analogs of the Stokes and Raman pulses in a conventional STIRAP. We now allow the hopping rates to change with time. The derivation of the fast-forward driving potential proceeds in the same manner as Section 3.3.5. The Schrodinger equation for an accelerated state T pp is... 

Fig. 4. Stability of carbon on different sites (A-D) on a pure nickel(l 11) surface (below) and a gold-alloyed nickel(l 11) surface (above). The probability of nucleation of graphite is determined by the stability of the adsorbed carbon atoms. The less stable the adsorbed carbon, the larger the tendency to react with adsorbed oxygen to form CO and the lower the coverage. On the pure nickel) 111) surface, the most stable adsorption configuration of carbon is in the threefold (hep) site (lower curve). The upper graph shows that carbon adsorption in threefold sites next to a gold atom is completely unstable (sites B and C), and even the threefold sites that are next-nearest neighbors (sites A and D) to the gold atoms are led to a substantial destabilization of the carbon. From Reference (79).

Consider a. plane square lattice Ising model with a spin variable s J = 1 associated with the site (i,j) and interactions between nearest-neighbor sites. Kaufman and Onsager3 4 have shown how the spin-spin correlation functions in an infinite lattice,... 

Let us consider the atomic processes that take place during chemical diffusion on three neighboring lattice planes. As in Figure 4-10, we label these planes p-, p, and p+ 1. n (= np(i)) designates the number density of species i on plane p such that = n°. The total number of nearest neighbor sites of ip on plane p— 1 (p+1) is... 

The diffusion of vacancies is uncorrelated for the same reasons given above for diffusion of the interstitial atoms. After each jump, a vacancy will have the possibility of jumping into any one of its 12 nearest-neighbor sites with equal probability. 

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