Fig. 1: Schematic crystal structure and x-ray diffraction results of Re3Ge7−xGax.

a A three-dimensional view of the orthorhombic structure of Re3Ge7. b Structure of Re3Ge7 projected perpendicular to the a-axis. The circles indicate the ReGe3 and Re2Ge4 building blocks. c Room temperature powder XRD patterns for the series of Re3Ge7−xGax samples. d–g Variation of a-, b-, c-axis lattice parameters and unit-cell volume of Re3Ge7−xGax as a function of the Ga content x.