The alkaline earth-palladium-germanides Sr3Pd4Ge4 and BaPdGe

Abstract

Abstract The germanides Sr3Pd4Ge4 and BaPdGe were obtained from high-temperature reactions in sealed niobium ampoules and their structures have been determined from single-crystal X-ray diffraction data: a=444.2(1), b=438.1(1), c=2472.2(7) pm, space group Immm, U3Ni4Si4 type, wR2=0.0471, 576 unique reflections, 25 parameters for Sr3Pd4Ge4 and a=677.09(8), space group P213, LaIrSi type, wR2=0.0322, 409 unique reflections, nine parameters for BaPdGe. Both germanides have pronounced three-dimensional [Pd4Ge4] δ− and [PdGe] δ− polyanionic networks with Pd–Ge bonding interactions. This is confirmed by the density functional theory (DFT)-based electronic structure investigations, the trends of charge transfer and crystal orbital overlap population (COOP) analyses.