Effective interactions multisite

Since, the surface energy curve is obtained for a pseudomorphic alloy on a fixed lattice of the substrate, its behavior can be related directly to the type of so-called effective interactions which are responsible for the ordering of A and B atoms on the surface. That is, if the multisite interactions are small in the system, which is usually the case for metallic alloys on a fixed lattice, the mixing energy can be written in terms of pair potentials between alloy... 

The surface orientation also plays a very important role in the surface alloy formation, since alloying is determined by effective interactions and the corresponding coordination numbers, Zi, which are surface specific. In some cases, especially when the substrate belongs to the IVb-VIIlb group in the periodic table, the multisite interactions may play an important role. In those cases, the surface energy curve will not have the simple parabolic shape presented in Fig. 4 and the alloying behavior may be more complex than described above. To have even a qualitative understanding one may therefore need further input. 

One of the major ingredient for the understanding of alloy phase stability is the configurational energy. Models have been proposed to represent the configurational energies in terms of effective multisite interactions, in particular effective pair interactions (EPls). 

CCR3 Receptor Structure. Chimera studies of CCR3 and CCRl receptors show that the N-terminal segments of CCR3 appear to be important for eotaxin binding (77). However, eotaxin remained an effective agonist at this chimeric receptor in either calcium flux or chemotaxis assays. These data are consistent with a multisite model for chemokine-chemo-kine receptor interaction. 

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