The energetics of icosahedral ordering in cholesteric liquid crystals are studied within the Landau mean-field approximation, in an attempt to describe the blue fog (blue phase III). We expand the free energy of a quasicrystalline phase in the high-chirality limit (coherence length much greater than pitch), and find that although it is energetically competitive with the cubic blue phases, no vertex-edge icosahedral phase is ever favored in this regime.

• Received 28 January 1986

DOI:https://doi.org/10.1103/PhysRevLett.56.1727