  This paper contains both recently published and original results concerning
the electronic structure, bonding and relevant properties of (Mg-Al)B2. We
analyse the electronic structure formation of bulk and surface states, study
the nuclear spin-lattice relaxation rates, compare the theoretical and
experimental estimates of the density of states at the Fermi level, and review
the electron-phonon coupling calculations. The analysis of optical properties
of MgB2 and AlB2 is also provided.
