Published online by Cambridge University Press: 01 February 2011
Electronic structures of hexagonal Zn-Mg-Y and Cd58Y13 compounds are studied by first-principles calculations. Both of the systems show deep pseudogap in the electronic density of states near the Fermi level and considered to be stabilized electronically. To illustrate bonding nature of electronic wavefunctions, the crystal orbital Hamilton population (COHP) is calculated for neighboring pairs of atoms in the unit cell. It is found that the bonding nature is changed from bonding to anti-bonding almost exactly at the Fermi level for Zn-Zn and Cd-Cd bonds. On the contrary, for Zn/Cd-Y bonds, both of the states below and above the pseudogap behave as bonding ones. Possible effects of the p-d hybridization are discussed.