Ab Initio Study on Electronic Structure of ZrB12 under High Hydrostatic   Pressure
  Using projector augmented wave approach within the generalized gradient approximation, we have studied the structural property and electronic structure of ZrB12. The calculated lattice constants and bulk modulus are in good agreement with the available experimental values. A detailed study of the electronic structure and the charge-density redistribution reveals the features of strong covalent B-B and weak covalent Zr-B bondings in ZrB12. The states at the Fermi level mainly come from the $\sigma$-$p_{y}$ and $\pi$-$p_{z}$ orbitals of boron atoms, which are slightly hybridized with the $t_{2g}$-$d_{xz}$ and $t_{2g}$-$d_{yz}$ orbitals of Zr atoms. As the increased hydrostatic pressure on ZrB12, the total density of states at the Fermi level decreases. 
Z. F. Hou