CHEMICAL BONDING AND MAGNETISM IN THE GERMANIDES HT-UCO2GE2, UGE3 ANDU3CO4GE7 FROM LOCAL SPIN-DENSITY FUNCTIONAL CALCULATIONS

The electronic and magnetic structures of HT-UCo2Ge2 (high temperature form), UGe3 and of the new intermetallic system U3Co4Ge7 are self-con sistently calculated within the local spin density functional theory u sing the augmented spherical wave (ASW) method. The influence of hybri disation on the chemical bonding and magnetic behaviour is discussed f rom the densities of states (DOS) as well as from the crystal orbital overlap population (COOP) which was recently combined with the ASW met hod. From this we address the modifications of both chemical bonding c haracteristics and of magnetic polarisations of uranium and cobalt in HT-UCo2Ge2 and UGe3, these two compounds being considered as the build ing blocks of U3Co4Ge7.