The orthorhombic structure of Y₃Co₂, a shift structure variation of the monoclinic Dy₃Ni₂ type

Y 3 co 2 crystallizes with a new orthorhombic structure type.Space group Pnnm (No 58); a = 12.248, b = 9.389 and 0 -3 1 c = 3.975A; z = 4, DX = 5.58 gem ' F.W. = 384.58grnol-' F(OOO) = 684 and µMoKa = 426 cm-1 • R = 0.10.The structure of Y 3 co 2 and of the earlier determined Dy 3 Ni 2 are shift structure variants.Both structures are characterized by bands of infinite length formed by joining four infinite trigonal prism columns.The arrangement of these bands is however different in the two structure types.Slicing one' of the structure types in blocks of equal size and shifting them with respect to one another leads to an atom arrangement characteristic of the other structure type.