1. Electronic structure of metals and alloys

1.1 General information on crystal bonding

The overall properties of a metal, as of any solid body, are essentially determined by the distribution of nuclei and valence electrons of the atoms that make it up. For example, the cohesion of a solid is always due to the electrical attraction between positively-charged nuclei and negatively-charged electrons. Magnetic effects are much weaker; the roles of gravitational and nuclear interactions are negligible.

A solid is stable if its energy is less than the sum of the energies of its constituent atoms, when they are infinitely far apart. The positive cohesive energy U of a solid is defined at 0 K by :