For a random sequence, the structure is called rHCP for random hexagonal close packing of 2D hexagonal planes of spheres. Any stack sequence gives the same compacity. On the third line of the table are listed the close packed structures : the cubic FCC phase ( ABCABC… stack sequence) and its hexagonal counterpart the HCP phase ( ABAB… stack sequence). One can imagine that even more complicated stacking sequences could be stabilised as well, forming periodic or aperiodic stacks. The third C36 Friauf-Laves phase corresponds to a longer stack sequence: ABACABAC…. As detailed here, they both correspond to two different stacking sequences: ABCABC… for C15 and ABAB… for C14. The C15 phase has a cubic symmetry and the C14 phase is its hexagonal counterpart. They all share the same composition in terms of coordination numbers (Z12:Z16=2:1). On the second line of the table are listed the TCP Friauf-Laves phases. More complex combinations of the square/triangle structural units give rise to quasicrystalline order with 12-fold symmetry. The obtained layered structures have a strong link with square/triangle tilings. They are both formed by combining structural units of the A15 phase (cubic volume, square in projection) and units of the Z phase (triangular prism, triangle in projection). The phase ( tetragonal space group) and the H phase ( orthorhombic space group) are related to the A15 phase and Z phase. In the first line, the A15 phase and Z phase are the simplest exemples of layered Frank and Kasper/TCP phases.
More infos and images are available by selecting a phase in the table.įirst column in the table corresponds to cubic structures and second column to their hexagonal version/counterpart.
#Crystalmaker stacking download
Simply download the corresponding CM file. Each phase can be visualized in 3D using CrystalMaker. Many of them have already been observed in soft matter systems (they are written in bold script in the summary table hereafter) … and other ones may be discovered one day. Here are summarized structural features for different TCP phases and related phases.
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