Revisiting the foundations of the quantum theory of atoms in molecules: Toward a rigorous definition of topological atoms

2009 ◽  
Vol 109 (4) ◽  
pp. 726-732 ◽  
Author(s):  
Payam Nasertayoob ◽  
Shant Shahbazian
Keyword(s):  
Quantum Theory ◽  
Atoms In Molecules ◽  
Rigorous Definition ◽  
Definition Of ◽  
Topological Atoms

scholarly journals A local-realistic model for quantum theory

2021 ◽  
Vol 477 (2250) ◽  
pp. 20200897
Author(s):  
Paul Raymond-Robichaud
Keyword(s):  
Wave Function ◽  
Quantum Theory ◽  
Realistic Model ◽  
Local Realism ◽  
Rigorous Definition ◽  
Definition Of

We provide a rigorous definition of local realism. We show that the universal wave function cannot be a complete description of a local reality. Finally, we construct a local-realistic model for quantum theory.

What’s in, what’s out? Towards a rigorous definition of the boundaries of benefit-cost analysis

2021 ◽  
pp. 1-17
Author(s):  
Daniel Acland
Keyword(s):  
Cost Analysis ◽  
Willingness To Pay ◽  
Low Cost ◽  
Consumer Sovereignty ◽  
Benefit Cost Analysis ◽  
Rigorous Definition ◽  
Pareto Criterion ◽  
Definition Of ◽  
Benefit Cost

Abstract Benefit-cost analysis (BCA) is typically defined as an implementation of the potential Pareto criterion, which requires inclusion of any impact for which individuals have willingness to pay (WTP). This definition is incompatible with the exclusion of impacts such as rights and distributional concerns, for which individuals do have WTP. I propose a new definition: BCA should include only impacts for which consumer sovereignty should govern. This is because WTP implicitly preserves consumer sovereignty, and is thus only appropriate for ‘sovereignty-warranting’ impacts. I compare the high cost of including non-sovereignty-warranting impacts to the relatively low cost of excluding sovereignty-warranting impacts.

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.

On the transferability of electron density in binary vanadium borides VB, V3B4 and VB2

2015 ◽  
Vol 71 (6) ◽  
pp. 777-787 ◽  
Author(s):  
Bürgehan Terlan ◽  
Lev Akselrud ◽  
Alexey I. Baranov ◽  
Horst Borrmann ◽  
Yuri Grin
Keyword(s):  
Quantum Theory ◽  
Crystal Structures ◽  
Electron Density ◽  
Critical Points ◽  
Atoms In Molecules ◽  
Model Systems ◽  
Suitable Model ◽  
Interatomic Distances ◽  
Systematic Analysis ◽  
A Charge

Binary vanadium borides are suitable model systems for a systematic analysis of the transferability concept in intermetallic compounds due to chemical intergrowth in their crystal structures. In order to underline this structural relationship, topological properties of the electron density in VB, V3B4 and VB2 reconstructed from high-resolution single-crystal X-ray diffraction data as well as derived from quantum chemical calculations, are analysed in terms of Bader's Quantum Theory of Atoms in Molecules [Bader (1990). Atoms in Molecules: A Quantum Theory, 1st ed. Oxford: Clarendon Press]. The compounds VB, V3B4 and VB2 are characterized by a charge transfer from the metal to boron together with two predominant atomic interactions, the shared covalent B—B interactions and the polar covalent B—M interactions. The resembling features of the crystal structures are well reflected by the respective B—B interatomic distances as well as by ρ(r) values at the B—B bond critical points. The latter decrease with an increase in the corresponding interatomic distances. The B—B bonds show transferable electron density properties at bond critical points depending on the respective bond distances.

scholarly journals ELECTRONIC STRUCTURE OF METHYLIDINESULFOXIDALCANES

2020 ◽  
pp. 106-113
Author(s):  
Наталья Петровна Русакова ◽  
Елена Михайловна Чернова ◽  
Владимир Владимирович Туровцев ◽  
Юрий Димитриевич Орлов
Keyword(s):  
Electronic Structure ◽  
Quantum Theory ◽  
Functional Groups ◽  
Atoms In Molecules

В рамках «квантовой теории атомов в молекулах» (QTAIM) определено электронное строение молекул ряда метилидинсульфоксидалканов n-C H-S(О)СН, где 1 ≤ n ≤ 10. Составлена качественная шкала электроотрицательностей функциональных групп. Within the framework of the «quantum theory of atoms in molecules» (QTAIM), the electronic structure of the molecules of a series of methylidinesulfoxidealkanes n-CH-S(О)СН, where 1 ≤ n ≤ 10, was determined. A qualitative scale of electronegativities of functional groups was compiled.

scholarly journals Regreso al vacío: sobre ausencia y desaparición social (Back to the void. Concerning absence and social disappearance)

2019 ◽  
Vol 9 (2) ◽  
pp. 183-197 ◽  
Author(s):  
Gabriel Gatti ◽  
Jaume Peris ◽  
Iñaki Robles Elong ◽  
Silvia Rodríguez Maeso ◽  
Ramón Sáez Valcárcel
Keyword(s):  
Rigorous Definition ◽  
Definition Of ◽  
Sobre Todo ◽  
The Disappeared

La ausencia es un tópico común en los textos que toman a la desaparición forzada o al desaparecido como objeto de interés. No es extraño, pues se han conseguido a partir de ese concepto resultados poderosos. Sin embargo, como en casi todo lo que se naturaliza, el contenido del concepto y de sus declinaciones ha perdido fuelle y cuesta saber de qué se habla cuando se habla de ausencia. Dentro del esfuerzo por construir una definición rigurosa de “desaparición social”, este texto regresa sobre el concepto, observa sus usos más instalados y sobre todo busca vías para volver a llenarlo de contenido. En este texto daremos algunos pasos en esa renovación. Absence is a common topic in the literature that analyzes forced disappearances and the disappeared. This is understandable because approaches from this concept have brought about remarkable insights. However, as it usually happens when something is naturalized, the concept’s content and its derivations have lost centrality and we find it hard to tell what’s the meaning of this concept. In an endeavor to develop a rigorous definition of “social disappearance”, this article looks back at the concept, focuses on its dominant uses and, above all, searches for ways to fill it with content. The present work moves forward with the renovation of this notion.

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