Hohenberg-Kohn Theorem

The Hohenberg-Kohn theorem is a fundamental concept in quantum chemistry stating that the properties of a many-electron system, like a molecule or atom, are uniquely determined by its electron density—the way electrons are distributed in space—rather than the complex wavefunction. This means that all the information needed to understand the system’s behavior can be obtained from its electron density alone. Consequently, this simplifies calculations of molecular structures and reactions, making it a cornerstone for methods like density functional theory that are used to study materials and chemical processes efficiently.