Crystal structures of isotypic aluminides CeRuAl and CeRhAl

The crystal structures of the compounds CeRuAl and CeRhAl were studied by single crystal X-ray diffraction. Both compounds crystallize in the orthorhombic LaNiAl type with space group Pnma (No. 62) and are related to the structure types of hexagonal ZrNiAl and orthorhombic TiNiSi. Parameters for CeRuAl and CeRhAl are: a = 7.2057(2) Å, b = 4.0589(1) Å, c = 15.8728(5) Å; RF = 0.023; a = 7.107(2) Å, b = 4.2237(10) Å, c = 15.965(3) Å; RF = 0.032, respectively.