ElektronendichtePartner

ElektronendichtePartner is a term used in theoretical and computational chemistry to denote a counterpart or contributor to the electron density within a molecular system. In practice, it refers to a fragment, atom, orbital, or functional group whose electron density is correlated with, or partitions, the total density in a way that highlights sharing or transfer of electrons between parts of a molecule.

The concept is often discussed in the context of density-partitioning schemes, such as Mulliken, Hirshfeld, or Bader’s atoms-in-molecules, where the total electron density is decomposed into contributions associated with predefined fragments. The ElektronendichtePartner is then the partner fragment that accounts for a significant portion of the local density or acts as a donor, acceptor, or polarization reservoir.

Calculation typically involves selecting a partitioning scheme and a region of interest, then identifying the fragment that shows strong density overlap or has characteristics indicating electron donation, withdrawal, or transfer. Quantitative measures such as density overlap integrals, transfer indices, or population analyses may be reported to characterize the partner.

Applications include analyzing bonding patterns, donor–acceptor interactions, charge-transfer processes, and catalysis. In materials science, the concept can aid understanding of charge transport and polarization effects. Etymologically, the term appears in German-language literature and is not a universally standardized quantity in international quantum-chemical practice; related ideas are often described using terms like density contributors or density fragments.