Spatial Ordering of Identical Spheres

FIGURE 4.1 Ordering in plane of identical spheres R radius. 

The distance between the center of the sphere and the neighbor is d=2R. Number of proximity neighbors of a reference sphere is called the coordination code or number (CN) of the center sphere (being the lattice mark). 

Therefore, this planar arrangement is provided for a particle CN=4, i.e., in which the parallel strings have the centers of spheres placed on a perpendicular line on the reticular strings direction. 

However, free spaces remain between plane netwoik particles, called interstices or voids. In (a)-type arrangement, the void shape is a square, defined by joining the centers of the four spheres from successive parallel strings, with the surface  

FIGURE 4.2 Deduction of the sphere radius of quadratic void from AA type (quadratic) plane network. 

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