The first aluminide with Ho4Ni10Ga21-type structure
Chem. Met. Alloys 6 (2013) 63-69
Svitlana PUKAS, Pavlo DEMCHENKO, Roman GLADYSHEVSKII
Tetralutetium decanickel henicosaaluminide, Lu4Ni10Al21, was synthesized by arc melting and its crystal structure was studied by X-ray powder diffraction. It is isotypic to Ho4Ni10Ga21: Pearson symbol mS70, space group C2/m, a = 20.7920(4), b = 4.0279(1), c = 15.4778(3) Å, β = 124.878(1)º. The structure of the Lu4Ni10Al21 compound belongs to a family of two-layer structures, where the atoms of each layer are situated at the centers of straight prisms built of atoms of the neighboring layers. The Lu and Ni atoms center pentagonal and trigonal prisms, respectively, whereas the Al atoms center square and pentagonal prisms in the ratio 15:6 in this description.
Projection of the structure of Lu4Ni10Al21 along  (nets of triangles, squares and pentagons at y = 0 and y = ½ are indicated)
Aluminum / Lutetium / Nickel / X-ray powder diffraction / Crystal structure / Crystal-chemical formulae