Chemical bonding from Wannier functions

Quantifying fundamental concepts of chemical bonding, such as ionicity, covalency, effective atomic charges, and the decomposition of cohesive energy into chemically interpretable contributions, remains a persistent challenge in theoretical chemistry. This work reviews a recently developed first-principles methodology based on Wannier functions possessing atomic orbital symmetry, which provides a rigorous framework for numerically characterizing these bonding attributes across diverse systems. We survey the method′s theoretical foundations and application to a wide range of materials, highlighting key results that validate its reliability and universality. Examples demonstrate how the approach captures essential physics of chemical bonding, and bridges conceptual models with quantitative analysis. By synthesizing the accumulated evidence, this review underscores the method′s utility as a robust tool for bonding analysis and discusses its limitations and future prospects. The bibliography includes 19 references.