 The vertex arrangement of the 16-cell honeycomb is called the D4 lattice or F4 lattice.The vertices of this lattice are the centers of the 3-spheres in the densest known packing of equal spheres in 4-space; its kissing number is 24, which is also the same as the kissing number in R4, as proved by Oleg Musin in 2003.The D lattice (also called D) can be constructed by the union of two D4 lattices, and is identical to the tesseractic honeycomb