Figure 1
From: Reduction of Thermal Conductivity by Nanoscale 3D Phononic Crystal
The structures of the isotopic nanoscale 3D phononic crystals - three dimensional periodic arrangements of 28Si and MSi atoms.
From (a) to (d), the period lengths of those 3D phononic crystals are 2, 4, 6 and 12 units, respectively. The lattice constant is 0.543 nm, that is, 1 unit represents 0.543 nm. In simulations, the periodic boundary condition is applied in all three directions.
