Quantum Theory of Atoms in Molecules Charge−Charge Flux−Dipole Flux Models for the Infrared Intensities of X2CY (X = H, F, Cl; Y = O, S) Molecules

2007 ◽  
Vol 111 (32) ◽  
pp. 7870-7875 ◽  
Author(s):  
Sergio H. D. M. Faria ◽  
João Viçozo da Silva ◽  
Roberto L. A. Haiduke ◽  
Luciano N. Vidal ◽  
Pedro A. M. Vazquez ◽  
...  
Keyword(s):  
Quantum Theory ◽  
Atoms In Molecules ◽  
Infrared Intensities ◽  
Charge Flux

Quantum Theory Atoms in Molecules Charge−Charge Flux−Dipole Flux Models for the Infrared Intensities of Benzene and Hexafluorobenzene

2009 ◽  
Vol 113 (27) ◽  
pp. 7972-7978 ◽  
Author(s):  
João Viçozo da Silva ◽  
Anselmo E. Oliveira ◽  
Yoshiyuki Hase ◽  
Roy E. Bruns
Keyword(s):  
Quantum Theory ◽  
Atoms In Molecules ◽  
Infrared Intensities ◽  
Charge Flux

Quantum Theory of Atoms in Molecules Charge–Charge Transfer–Dipolar Polarization Classification of Infrared Intensities

2017 ◽  
Vol 121 (42) ◽  
pp. 8115-8123 ◽  
Author(s):  
Leonardo J. Duarte ◽  
Wagner E. Richter ◽  
Arnaldo F. Silva ◽  
Roy E. Bruns
Keyword(s):  
Quantum Theory ◽  
Charge Transfer ◽  
Atoms In Molecules ◽  
Infrared Intensities

Ab initio charge density analysis of (B6C)2– and B4C3 species — How to describe the bonding pattern?

2006 ◽  
Vol 84 (5) ◽  
pp. 771-781 ◽  
Author(s):  
Cina Foroutan-Nejad ◽  
Gholam Hossein Shafiee ◽  
Abdolreza Sadjadi ◽  
Shant Shahbazian
Keyword(s):  
Quantum Theory ◽  
Carbon Atom ◽  
Charge Density ◽  
Ab Initio ◽  
Atoms In Molecules ◽  
Central Carbon Atom ◽  
B3lyp Method ◽  
Central Carbon ◽  
Density Analysis ◽  
Concrete Ring

In this study, a detailed topological charge density analysis based on the quantum theory of atoms in molecules (QTAIM) developed by Bader and co-workers, has been accomplished (using the B3LYP method) on the CB62– anion and three planar isomers of the C3B4 species, which had been first proposed by Exner and Schleyer as examples of molecules containing hexacoordinate carbon atoms. The analysis uncovers the strong (covalent) interactions of boron atoms as well as the "nondirectional" interaction of central carbon atom with those peripheral atoms. On the other hand, instabilities have been found in the topological networks of (B6C)2– and B4C3(para) species. A detailed investigation of these instabilities demonstrates that the topology of charge density has a floppy nature near the equilibrium geometries of the species under study. Thus, these species seems to be best described as complexes of a relatively concrete ring containing boron or carbon atoms and a central carbon atom that is confined in the plane of the molecule, but with nondirectional interactions with the surrounding atoms.Key words: hypervalency, hexacoordinate carbon, quantum theory of atoms in molecules, charge density analysis, ab initio methods.

scholarly journals Decomposition of d- and f-Shell Contributions to Uranium Bonding from the Quantum Theory of Atoms in Molecules: Application to Uranium and Uranyl Halides

Inorganics ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 88 ◽  
Author(s):  
Jonathan Tanti ◽  
Meghan Lincoln ◽  
Andy Kerridge
Keyword(s):  
Quantum Theory ◽  
Electronic Structures ◽  
Density Functional ◽  
Covalent Bond ◽  
Vibrational Frequencies ◽  
Atoms In Molecules ◽  
High Symmetry ◽  
Strong Correlations ◽  
Bond Stability ◽  
Fluoride Ligands

The electronic structures of a series of uranium hexahalide and uranyl tetrahalide complexes were simulated at the density functional theoretical (DFT) level. The resulting electronic structures were analyzed using a novel application of the Quantum Theory of Atoms in Molecules (QTAIM) by exploiting the high symmetry of the complexes to determine 5f- and 6d-shell contributions to bonding via symmetry arguments. This analysis revealed fluoride ligation to result in strong bonds with a significant covalent character while ligation by chloride and bromide species resulted in more ionic interactions with little differentiation between the ligands. Fluoride ligands were also found to be most capable of perturbing an existing electronic structure. 5f contributions to overlap-driven covalency were found to be larger than 6d contributions for all interactions in all complexes studied while degeneracy-driven covalent contributions showed significantly greater variation. σ-contributions to degeneracy-driven covalency were found to be consistently larger than those of individual π-components while the total π-contribution was, in some cases, larger. Strong correlations were found between overlap-driven covalent bond contributions, U–O vibrational frequencies, and energetic stability, which indicates that overlap-driven covalency leads to bond stabilization in these complexes and that uranyl vibrational frequencies can be used to quantitatively probe equatorial bond covalency. For uranium hexahalides, degeneracy-driven covalency was found to anti-correlate with bond stability.

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