The correlation theory of the chemical bond

0474774 - ÚFCH JH 2018 RIV GB eng J - Journal Article
Szalay, S. - Barcza, G. - Szilvási, T. - Veis, Libor - Legeza, Ö.
The correlation theory of the chemical bond.
Scientific Reports. Roč. 7, MAY 2017 (2017), č. článku 2237. ISSN 2045-2322. E-ISSN 2045-2322
R&D Projects: GA ČR GA16-12052S
Institutional support: RVO:61388955
Keywords : density matrix * quantum chemistry * theoretical model
OECD category: Physical chemistry
Impact factor: 4.122, year: 2017
Method of publishing: Open access

The quantum mechanical description of the chemical bond is generally given in terms of delocalized bonding orbitals, or, alternatively, in terms of correlations of occupations of localised orbitals. However, in the latter case, multiorbital correlations were treated only in terms of two-orbital correlations, although the structure of multiorbital correlations is far richer, and, in the case of bonds established by more than two electrons, multiorbital correlations represent a more natural point of view. Here, for the first time, we introduce the true multiorbital correlation theory, consisting of a framework for handling the structure of multiorbital correlations, a toolbox of true multiorbital correlation measures, and the formulation of the multiorbital correlation clustering, together with an algorithm for obtaining that. These make it possible to characterise quantitatively, how well a bonding picture describes the chemical system. As proof of concept, we apply the theory for the investigation of the bond structures of several molecules. We show that the non-existence of well-defined multiorbital correlation clustering provides a reason for debated bonding picture.
Permanent Link: http://hdl.handle.net/11104/0271726