Interpretation of the reduced density gradient

ABSTRACT

An interpretation of the reduced density gradient in terms of the bosonic kinetic energy density is presented. Contrary to other bonding indicators based on the kinetic energy density, such as the localised orbital locator (LOL) or the electron localisation function, the reduced density gradient is not only able to identify covalent bondings, but also ionic and non-covalent interactions. This study reveals that the critical points of the reduced density gradient are closely connected with those of the LOL and with the roots of the one-electron potential.

GRAPHICAL ABSTRACT

KEYWORDS:

• Kinetic-energy density
• reduced density gradient
• ELF
• LOL
• OEP

Acknowledgements

The authors wish to thank Prof. Andreas Savin for his endless strength and discussions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental data

Supplemental data for this article can be accessed at: http://dx.doi.org/10.1080/00268976.2015.1123777.

Notes

1. The index of a critical point is defined as the number of positive eigenvalues of the Hessian matrix at the position of the critical point. In ${\mathbb{R}}^3$, maxima, 1-saddle, 2-saddle and minima critical points have indices 0,1,2 and 3, respectively.

Additional information

Funding

This work was supported partially by the framework of CALSIMLAB [public grant ANR-11-LABX-0037-01] overseen by the French National Research Agency (ANR) as part of the ‘Investissements d’Avenir’ program (reference: ANR-11-IDEX-0004-02).