  In this paper, we present two deterministic leader election algorithms for
programmable matter on the face-centered cubic grid. The face-centered cubic
grid is a 3-dimensional 12-regular infinite grid that represents an optimal way
to pack spheres (i.e., spherical particles or modules in the context of the
programmable matter) in the 3-dimensional space. While the first leader
election algorithm requires a strong hypothesis about the initial configuration
of the particles and no hypothesis on the system configurations that the
particles are forming, the second one requires fewer hypothesis about the
initial configuration of the particles but does not work for all possible
particles' arrangement. We also describe a way to compute and assign-local
identifiers to the particles in this grid with a memory space not dependent on
the number of particles. A-local identifier is a variable assigned to each
particle in such a way that particles at distance at most each have a different
identifier.
