On phase-equilibria in molecules

摘要

Information theory (IT) is applied to explore electronic phase-equilibria in molecules. The modulus and phase parts of electronic states, giving rise to the particle probability and current densities, respectively, delineate two basic degrees-offreedom in the generalized (quantum) IT treatment of molecular states. The classical and non-classical contributions to the resultant information content are accounted for in the complementary Shannon and Fisher measures. These quantum descriptors are then applied in the "vertical" information principles, which determine the density-constrained molecular equilibria. A close parallelism between the vertical maximum-entropy and minimum-energy principles of quantum mechanics and their thermodynamic analogs is emphasized. The relation between the probability and phase distributions in the "horizontal" (probability-unconstrained) equilibria is examined and solutions of the (energy-unconstrained) orbital variational rules for the extremum entropy/information are shown to involve the spatial phase related to electron density. Selected properties of such molecular equilibrium states are explored.