Density Functional Theory (DFT) is a quantum mechanical modelling method, used in physics and chemistry to investigate the electronic structure (principally the ground state) of many-body systems, in particular atoms, molecules, and the condensed phases. This book provides current research in the study of the principles, applications and analysis of Density Functional Theory (DFT). Topics discussed include density functional treatment of interactions and chemical reactions at interfaces; applications of DFT calculations to lithium carbenoids and magnesium carbenoids; thermoelectric properties of low-dimensional materials by DFT; using DFT computations on the radical scavenging activity studies of natural phenolic compounds; polarizability of C60/C70 fullerene [2+1]- and [1+1]-adducts; DFT application to the calculation of properties of di- and trimethylnaphthalenes; transport calculations of organic materials; the evolution of DFT; the capabilities of DFT for materials design of alloys; and the fundamentals of energy density functionality in nuclear physics.