Twenty rare-earth gold gallides, RAu 3 Ga 7 (ScRh 3 Si 7-type, space group R-3c, Z = 6, hR66), RAu 3±x Ga 3±x (YCd 6-type, space group Im-3, Z = 24, cI68), RAu 1+x Ga 2-x (MgCuAl 2-type, space group Cmcm, Z = 4, oS16) (R = Gd-Tm) and R 14 Au 34+x Ga 17-x (Gd 14 Ag 51-type, space group P6/m, Z = 1, hP65) (R = Er, Tm), were synthesized by arc-melting, followed by annealing at 400-600ºC. Six phases RAu 1+x Ga 3-x (BaAl 4-type, space group I4/mmm, Z = 2, tI10) (R = Gd) and R 3 Au 3+x Ga 8-x (La 3 Al 11-type, space group Immm, Z = 2, oI26) (R = Tb-Tm) were prepared by the flux method. Their crystal structures were studied by X-ray powder or single crystal diffraction. Structural peculiarities, coordination and interaction of the atoms in the investigated compounds are briefly discussed. Rare-earth intermetallics / Ternary gallides / Crystal growth / Single crystal / X-ray diffraction / Crystal structure Experimental details Starting materials for the synthesis of the R-Au-Ga alloys were rare-earth ingots (R > 99.9 wt.%), gold plate (99.99 wt.%) and gallium pieces (99.999 wt.%). Samples with a total weight of 300 mg were prepared by arc-melting buttons in a water-cooled copper crucible with a tungsten electrode under a purified argon atmosphere, using Ti/Zr as a getter. The products were turned over and re-melted at least three times in order to ensure homogeneity. Fragments of
