Chapter 7 - Information-theoretic concepts in theory of electronic structure and chemical reactivity

Abstract

The orbital and local information networks are introduced and their entropy (covalency) and information (iconicity) descriptors are summarized. The mixed states of embedded molecular fragments are explored, communications in interacting subsystems are discussed, and probability propagations in alternative donor–acceptor reactive complexes are qualitatively examined. The explicit and implicit time dependencies of molecular wavefunctions are identified, and the effective probability velocity and acceleration concepts are proposed. Continuities of wavefunction components and probability/current distributions are tackled and the resultant gradient information is shown to represent the dimensionless kinetic energy of electrons. This allows one to interpret the minimum energy principle of thermodynamics as an equivalent information principle. Hypothetical stages of chemical reactions involving the entangled (bonded) or disentangled (nonbonded) reactants are discussed, and the in situ charge-transfer criteria are approached in both the energy and resultant-information descriptions. The molecular virial theorem is used to interpret changes in the overall gradient information accompanying the bond formation processes and chemical reactions.