| Abstract Scope |
Density Functional Theory (DFT) enables the practical application of quantum mechanics to complex systems by indirectly incorporating electron-electron, electron-phonon, and phonon-phonon interactions through electron density. Zentropy theory builds on this by treating total entropy as the sum of Gibbs configurational entropy among configurations and the quantum entropy of individual configurations. Rather than individual quantum states, Zentropy theory considers DFT-derived ground-state and symmetry-breaking non-ground-state configurations. The partition function of each configuration is evaluated using its Helmholtz energy to account for its quantum entropy. Since all configurations share the same number of particles, volume, and temperature (NVT) in a canonical ensemble, Zentropy theory predicts the Helmholtz energy of a homogeneous system—whether stable, metastable, or unstable—as a function of NVT. This forms a Helmholtz energy landscape with apexes and basins, enabling evaluation of thermodynamic stability, kinetic barriers, and driving forces between states, with relevance to non-equilibrium thermodynamics. |