Crystal structure of the compound Nd5Ag0.5Si3.5

Abstract Nd 5 Ag 0.5 Si 3.5 has the orthorhombic, Sm 5 Ge 4 -type structure, with space group Pnma , a = 7.645(2) A , b = 15.040(3) A , c = 7.881(2) A , z = 4, R w = 0.046 for 905 unique reflections (KM-4 autodiffractometer, Mo Kα radiation). The coordination polyhedra of neodymium atoms have 14–17 apices. The silver and silicon atoms occupy the centres of trigonal and tetragonal prisms having three and one additional atoms respectively. The relation between Nd 5 Ag 0.5 Si 3.5 , Nd 5 Si 4 and some ternary compounds with Sm 5 Ge 4 type is discussed.