Hexagonal Yb₆Cr_4+xAl_43-x(x=1.76) with a new structure type

The title compound contains one Yb, two Cr and seven A1 sites, one of which is about half occupied by Cr. The coordination polyhedron of Yb has the composition [Cr(A1,Cr)2All3Yb], while those around Cr are [All0Yb2] and [Al12], and that around the mixed site is [A19Yb3]