Electronic Structure of Metallic Beryllium

Band structure of metallic Be is calculated at various values of the lattice constants with proper emphasis on the deviation from the free electron model. It is found that Be keeps to be a metal up to the lattice constant by 1.6 times as large as the normal lattice. The density-of-states at the normal lattice has a deep valley at the Fermi energy. The charge distribution of conduction electrons in the real space is more concentrated along a line connecting the atoms in the direction of the c -axis. There seems to be a kind of the energy separation between a bonding and an anti-bonding orbitals due to a strong hybridyzation of s and p wave functions. The calculated value of the coefficient of the electronic specific heat is 0.145 mJ/mole·deg 2 , while the observed value is 0.171 mJ/mole·deg 2 , so that the enhancement factor is determined as 0.18. The calculated dimensions and the shape of the Fermi surfaces agree well with experiment.