A charge density study of the intermetallic compound MgCu₂ by the maximum entropy method

The charge density distribution of the intermetallic compound MgCu₂ is obtained by the maximum entropy method (MEM) from the synchrotron powder diffraction data. In the MEM charge density map, the overlap of electron densities was clearly observed between the neighbouring Cu atoms. This clearly shows that there is a rather strong covalent bond between Cu-Cu atoms. It is also found that the Cu-Cu bonding is along the very well known kagome net, which characterizes the Laves phase structure. At least, in the case of MgCu₂, the kagomé network is the electronic network in reality rather than a geometrical concept to represent structural characteristics of Laves phase compounds.