Metallic systems are ubiquitous in daily life. They play key roles, for example, in the chemistry of many biomolecules, ionic solutions, nanoparticles, and catalytic processes. They may be in solid, liquid, or gaseous form. The interactions of other molecules with metal surfaces are of considerable importance. Each of these topics is addressed in Metallic Systems. As we have entered the age where theoretical approaches are sufficiently mature to complement and guide experiments in many areas, an understanding of the theoretical tools and approaches to studying metallic systems is essential....