Its atomic radius is 0.190 nm and the (+1) ionic radius is 0.95 nm. In the solid state Sodium has a body-centered cubic crystal structure with a = 0.428 nm and a nearest neighbor distance of 0.371 nm.

This helps to visualise the structure. A two-dimensional model for the ionic lattice in sodium chloride A 2D model shows the arrangement of one layer of ions but it does have a major additional ...