The monoclinic Al45Cr7 revisited

A new unit cell with a = 2.0595 nm, b = 0.7574 nm, c = 1.0949 nm and β = 107.34° is proposed for the monoclinic Al45Cr7 in which icosahedra form chains in the monoclinic direction as well as triangular chains on (111¯). The main building block in the monoclinic Al45Cr7, the orthorhombic ɛ-Al4Cr, and the hexagonal μ-Al4Cr is the 2I3 cluster consisting of 2 vertex-linked I3 clusters which in turn consists of 3 vertex-connected icosahedra. The arrangement of 2 such clusters is similar in the former two phases but slightly different in the third.