Bader's Theory of Atoms in Molecules

Bader's Theory of Atoms in Molecules (AIM) proposes that molecules can be understood by analyzing their electron density—a measure of where electrons are likely to be found. According to AIM, the boundaries of atoms within a molecule are defined by specific regions called "zero-flux surfaces," where the electron density gradient is zero. These boundaries effectively partition the molecule into individual atoms, allowing us to study atomic properties and interactions inside molecules without relying on traditional chemical definitions. This approach provides a rigorous, physically meaningful way to understand chemical bonding and molecular structure based on electron distribution.