Crystal structure, magnetism, and bonding of the hexagonal compounds Pd_(1.63)Mn_(0.37)Si and Pd_(1.82)Mn_(0.18)Ge related to the Fe₂P structure

We have used single crystal X-ray diffraction methods to establish the crystal structures of a compound in the Pd-Mn-Si system and in the Pd-Mn-Ge system. The title compounds have structures related to the Fe$_2$P structure type and are ferromagnetic with Curie temperatures above the room temperature. Density functional electronic structure calculations help to understand the nature of the local moment ferromagnetism in these compounds. However neither the electronic structure calculations nor the magnetic measurements provide any evidence of half-metallic behavior.