Interpretation of so-called icosahedral and decagonal quasicrystals of alloys showing apparent icosahedral symmetry elements as twins of an 820-atom cubic crystal

AbstractA summary is presented of the arguments indicating that the so-called icosahedral and decagonal quasicrystals of MnAl6 and other alloys are twins of a cubic crystal with 820 atoms in the unit cube such that the complex of small individual crystallites has icosahedral or decagonal symmetry. The proposed 820-atom cubic crystal has a structure that is similar to that of other intermetallic compounds with complex structures involving clusters of metal atoms with approximate icosahedral symmetry