Quantum Theory

This book presents the main actual theories of matter, mainly the density function theory (DFT) for fermions, the Bose-Einstein condensation (BEC) for bosons, and chemical bonding as a special realization of the first two so-called mixed fermionic-bosonic states. It covers the modern and ultimately developed quantum theories involving the key concepts of density, condensation, and bonding. The book compiles, for the first time, the density functional theory with Bose-Einstein condensation and chemical bonding theories in a fresh and novel perspective.