Figure 8
Coordinate x1 of tetrahedral Al2 (light blue) and Si2 (dark blue) atoms of geometrically optimized (PBE) superstructures with labels M25 #2 (circles), M33 #1 (diamonds), M40 #1 (squares) and M50 #1 (triangles). The displacive and occupational modulation functions follow the same trend, allowing a description of the solid solution range by a unified superspace model. Dashed lines indicate trend lines fitted by hand. |