THE NEW TERNARY INTERMETALLIDE WITH A GIGANT UNIT CELL IN THE Nd-Ru-Sn SYSTEM. J. Stepien-Damm^*, P. Salamakha, O. Bodak. ^*Institute for Low Temperature and Structure Research, Polish Academy of Sciences. Okolna 2, Wroclaw, Poland; Inorganic Chemistry Department, L'viv State University, Kyryla and Mefodiya str. 6, 290005 L'viv, Ukraine

The structure of Nd₁₂₅Ru_67-xSn₉₀ was studied by single crystal X-ray diffraction. The title compound crystallizes in the cubic system, space group Fm-3m, a=30.785A, Z=4. Nd₁₂₅Ru_67-xSn₉₀ is the first representative of a new structure type in the ternary intermetallic systems, however is related to Tb₁₁₇Fe₅₂Ge₁₁₂ type of structure[1]. The differences are due to composition as well as the additional Ru atoms in 4(b) position in neodymium rhutenium tin alloy, which in Tb₁₁₇Fe₅₂Ge₁₁₂ is not filled. Hence, the number of atoms in the unit cell increases from 1124 to 1128. Coordination polyhedra for additional Ru atoms are cubes.

[1] V.K. Pecharsky, O. Bodak, V.K. Belsky, P.K. Starodub, I.R. Mokra, E.I. Gladyshevsky, Kristallographya,vol.2,(1987),344-348