Bonding Analyses in the Broad Realm of Intermetallics: Understanding the Role of Chemical Bonding in the Design of Novel Materials

The design of solids with tailored material properties requires a thorough understanding of their electronic structures. Examining the latter typically includes chemical-bonding analyses, which can reveal interatomic interactions and, thereby, explain remarkable structural and compositional features. Over the years, the nature of bonding was also considered to account for certain electronic peculiarities; yet, a direct connection between bonding and material properties such as electrical transport remains elusive due to fundamental reasons. To elucidate this problem, we carried out bonding analyses for a series of intermetallics chosen to reflect widely diverse bonding situations and analyzed by both wave function-based Löwdin charges and Crystal Orbital Bond Indices (COBI). In doing so, we established a library of integrated COBI values (ICOBI = quantum-chemical bond orders) as a guide for future analyses, whereas the outcome of our explorations clearly shows that the attempt to relate phenomena in the electronic band structure to the nature of bonding can be misleading.