In-Situ Electronegativity and the Bridging of Chemical Bonding Concepts
Journal article, 2021

One challenge in chemistry is the plethora of often disparate models for rationalizing the electronic structure of molecules. Chemical concepts abound, but their connections are often frail. This work describes a quantum-mechanical framework that enables a combination of ideas from three approaches common for the analysis of chemical bonds: energy decomposition analysis (EDA), quantum chemical topology, and molecular orbital (MO) theory. The glue to our theory is the electron energy density, interpretable as one part electrons and one part electronegativity. We present a three-dimensional analysis of the electron energy density and use it to redefine what constitutes an atom in a molecule. Definitions of atomic partial charge and electronegativity follow in a way that connects these concepts to the total energy of a molecule. The formation of polar bonds is predicted to cause inversion of electronegativity, and a new perspective of bonding in diborane and guanine−cytosine base-pairing is presented. The electronegativity of atoms inside molecules is shown to be predictive of pKa.

molecular orbital theory

energy decomposition analysis

quantum chemical topology

chemical bonding

pK prediction a


Stefano Racioppi

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

Martin Rahm

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

Chemistry - A European Journal

0947-6539 (ISSN) 1521-3765 (eISSN)

Vol. In Press

Subject Categories

Atom and Molecular Physics and Optics

Theoretical Chemistry

Condensed Matter Physics



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