Journal of Mathematical Chemistry

, Volume 45, Issue 3, pp 776–789 | Cite as

Manifestations of Pauli exclusion principle in communication-theory of the chemical bond

  • Roman F. Nalewajski
Original Paper


The implications of the Pauli exclusion principle for the entropy/informa- tion indices of the chemical bond formulated within the communication theory approach are explored. The spatial information channels in the local, two-electron resolution are derived for the singlet and triplet states of two electrons, modeling the chemical bonding and non-bonding states in a molecule, respectively. Their average conditional-entropy (covalency) and mutual-information (ionicity) descriptors are compared against those characterizing the separate atoms and an upper-bound to the information-theoretic bond-order for the molecular orbital “events” is determined. An illustrative application to AO channels in H2 generates numerical values of the information-theoretic indices for this prototype covalent bond. The molecular information systems are interpreted as the ensemble averages of the elementary deterministic (zero-covalency) information networks. Examples of such a channel synthesis include model binary channels and that representing the elementary valence-bond (VB) covalent structure in H2. The ensemble representation of the spin channel for the triplet state of two electrons, averaged over the three spin-projection components, offers an entropic perspective on the spin-pairing in the bond-formation process. The spin-paired (singlet) communication system is obtained by maximizing in the ensemble-average communication system of the triplet state the information-flow (ionicity) to its capacity level.


Bond indices Chemical bonding Communication theory Covalent/ionic components Elementary deterministic channels Ensemble of communication channels Hydrogen molecule Information theory Molecular communication systems Pauli exclusion principle Singlet channels Theory of chemical bonds Triplet channels 


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Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  1. 1.Department of Theoretical ChemistryJagiellonian UniversityCracowPoland

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