GGA+U method investigating structural and chemical bond properties of CeB6 and EuB6

The structural and chemical bond properties of CeB6 and EuB6 have been calculated by means of an all-electron full-potential linearized augmented plane wave (FPLAPW) and so-called GGA+U method, which are implemented within the EXCITING code. The calculated results indicate that concerning both CeB6 and EuB6, the optimized lattice constant, fitted bulk modulus, calculated spin magnetic moment and correlation energy parameter are in good agreement with experimental data. In addition, although the number of 4f electrons in Ce atom is different from that in Eu atom, the CeCe and EuEu bonds are mainly ionic bond, Ce (Eu)−B bonding includes ionic and covalent bond characteristics while the bonding between the nearest-neighbor B atoms (B1 and B2, B3 and B4) has a stronger covalent character than that of the next-nearest B bonds (B2 and B3).