Electron density and its reduced density gradient in the study of π–π interactions.
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| Title: | Electron density and its reduced density gradient in the study of π–π interactions. |
|---|---|
| Authors: | Morales‐Pumarino, Daniela1 (AUTHOR), Barquera‐Lozada, José E.1 (AUTHOR) jebarque@unam.mx |
| Source: | International Journal of Quantum Chemistry. Sep2023, Vol. 123 Issue 18, p1-10. 10p. |
| Subjects: | Electron density, Dispersive interactions, Kinetic energy, Biomaterials, Density functional theory |
| Abstract: | π−π interactions are unique dispersive interactions that are important for biological systems and materials, but the study of this interaction is not trivial. It is well‐known that density functional theory (DFT) does not describe these interactions correctly and only with empirical dispersion corrections, it produces accurate energies. Moreover, little is known about the error in the electron density (ρr). Non‐Covalent Interaction method (NCI) has been used to analyze π stacking from the electron density. However, for these interactions, the information that can be extracted with this method is quite limited. We compare the DFT and CCSD intermolecular ρr. The correlation between both densities is close to one, but DFT underestimates its value. To evaluate, if the strength of the π−π interaction can be qualitatively inferred from density related scalar fields, we study the correlation between these fields (ρr multiplied by the sign of the second eigenvalue of its hessian, signλ2ρ, the laplacian of ρr, ∇2ρr, the virial field, Vr, the Lagrangian, Gr, and the Hamiltonian, Kr, kinetic energy density) and the interaction energy. Surprisingly, all the scalar fields have a better correlation with the energy than signλ2ρ. This quantity is normally plotted over the reduced density gradient (RDG) isosurface in the NCI method to get an insight of intermolecular interactions, but the other scalar fields give a better picture of the energetic nature of π−π interactions. Moreover, we show that signλ2ρ cannot be used as an indicator of repulsive interactions (positive values), because for the studied π systems, the more energetic the interaction is, the more positive signλ2ρ. [ABSTRACT FROM AUTHOR] |
| Copyright of International Journal of Quantum Chemistry is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
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| Header | DbId: egs DbLabel: Engineering Source An: 169783269 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Electron density and its reduced density gradient in the study of π–π interactions. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Morales‐Pumarino%2C+Daniela%22">Morales‐Pumarino, Daniela</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Barquera‐Lozada%2C+José+E%2E%22">Barquera‐Lozada, José E.</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> jebarque@unam.mx</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22International+Journal+of+Quantum+Chemistry%22">International Journal of Quantum Chemistry</searchLink>. Sep2023, Vol. 123 Issue 18, p1-10. 10p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Electron+density%22">Electron density</searchLink><br /><searchLink fieldCode="DE" term="%22Dispersive+interactions%22">Dispersive interactions</searchLink><br /><searchLink fieldCode="DE" term="%22Kinetic+energy%22">Kinetic energy</searchLink><br /><searchLink fieldCode="DE" term="%22Biomaterials%22">Biomaterials</searchLink><br /><searchLink fieldCode="DE" term="%22Density+functional+theory%22">Density functional theory</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: π−π interactions are unique dispersive interactions that are important for biological systems and materials, but the study of this interaction is not trivial. It is well‐known that density functional theory (DFT) does not describe these interactions correctly and only with empirical dispersion corrections, it produces accurate energies. Moreover, little is known about the error in the electron density (ρr). Non‐Covalent Interaction method (NCI) has been used to analyze π stacking from the electron density. However, for these interactions, the information that can be extracted with this method is quite limited. We compare the DFT and CCSD intermolecular ρr. The correlation between both densities is close to one, but DFT underestimates its value. To evaluate, if the strength of the π−π interaction can be qualitatively inferred from density related scalar fields, we study the correlation between these fields (ρr multiplied by the sign of the second eigenvalue of its hessian, signλ2ρ, the laplacian of ρr, ∇2ρr, the virial field, Vr, the Lagrangian, Gr, and the Hamiltonian, Kr, kinetic energy density) and the interaction energy. Surprisingly, all the scalar fields have a better correlation with the energy than signλ2ρ. This quantity is normally plotted over the reduced density gradient (RDG) isosurface in the NCI method to get an insight of intermolecular interactions, but the other scalar fields give a better picture of the energetic nature of π−π interactions. Moreover, we show that signλ2ρ cannot be used as an indicator of repulsive interactions (positive values), because for the studied π systems, the more energetic the interaction is, the more positive signλ2ρ. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of International Journal of Quantum Chemistry is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1002/qua.27051 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 10 StartPage: 1 Subjects: – SubjectFull: Electron density Type: general – SubjectFull: Dispersive interactions Type: general – SubjectFull: Kinetic energy Type: general – SubjectFull: Biomaterials Type: general – SubjectFull: Density functional theory Type: general Titles: – TitleFull: Electron density and its reduced density gradient in the study of π–π interactions. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Morales‐Pumarino, Daniela – PersonEntity: Name: NameFull: Barquera‐Lozada, José E. IsPartOfRelationships: – BibEntity: Dates: – D: 15 M: 09 Text: Sep2023 Type: published Y: 2023 Identifiers: – Type: issn-print Value: 00207608 Numbering: – Type: volume Value: 123 – Type: issue Value: 18 Titles: – TitleFull: International Journal of Quantum Chemistry Type: main |
| ResultId | 1 |
