Quantum chemistry has developed a rich set of descriptors—bond dissociation energy, electron density, bond order, electron localization function (ELF), and en tanglement entropy—to characterize chemical bonding, yet these descriptors are often framed in disconnected formalisms and lack a unified ontological foundation. Energy-Efficiency Theory (EET) offers a complementary framework based on energy monism, where all stable structures are configurations of constrained-state energy. In this paper, we systematically map the core concepts of quantum chemistry onto their EET counterparts, providing a unified energy-ontological language for chemical bonding. We show that: (1) the bond dissociation energy is physically identical to the EET constraint barrier; (2) the normalized constrained potential shares a one-to one spatial correspondence with the electron density; (3) the bond order can be interpreted as the overlap of normalized constrained potentials; (4) the local en ergy ratio at the bond critical point (ηBCP) distinguishes bond types via the degree of electron localization; and (5) information-based bond descriptors align with the EET notions of constraint barrier and energy texture. This mapping provides a conceptually economical, cross-scale unified language for chemical bonding, resolving the fragmentation of formalisms in quantum chemistry. Due to the unavailability of original computational output files, all quantitative validation data (numerical tables, regression analyses, and R2 values) have been removed in this version. The present document serves as a purely theoretical framework.
Hongpu Yang (Sun,) studied this question.