ИСТИНА

The compound Ce3Rh7Al29 of the new structure type crystallizes in orthorhombic space group (SG) Cmcm, Pearson symbol oC156 with a=9.1570(4), b=31.3790(14), с=8.9414 (17) Е, V=2569.2(17) Е3. Intermetallics Ce2Rh3Al14 has a tetragonal structure closely related to Ce2Ru3Al15†, SG I41/amd, Pearson symbol tI136, a=9.0000(15), c=31.7640(11) Е), V=2572.9(6) Е3. Three cerium atoms (4c site) in Ce3Rh7Al29 and two cerium atom (8e site) in Ce2Rh3Al14 are coordinated by 18 and 20 Rh and Al atoms, forming the 3D- frameworks of large icosahedral voids. This feature resembles the high coordinated Ce environment seen in CeRh4Al15.7 and CeRh2Al10. With the exception of the disordered Ce1 in Ce3Rh7Al29, the closest Ce-Ce contacts in both compounds are about 4.5 A.