On the separation of the information content of the Fermi and Coulomb holes and their influence on the electronic properties of molecular systems. (4th March 2019)

• Record Type: Journal Article
• Authors: Rincon, Luis; Javier Torres, F.; Becerra, Marcos; Liu, Shubin; Fritsch, Alain; Almeida, Rafael
• Is Part Of: Molecular physics. Volume 117:Number 5(2019)
• Page Start: 610
• Page End: 625
• Publication Date: 2019-03-04
• Subjects: Electron localisation -- Fermi hole -- Coulomb hole -- electron correlation -- Kullback–Leibler divergence; Molecules -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Molécules -- Périodiques; Chimie physique et théorique -- Périodiques; 539.6.05
• DOI: 10.1080/00268976.2018.1530462
• Languages: English
• ISSNs: 0026-8976

Abstract

ABSTRACT: In this paper, two information-based functions are employed as a real space measure of the Fermi and Coulomb holes for same-spin electrons. The first one is the information content of the Exchange-Correlation hole, calculated from the Kullback–Leibler divergence of the same-spin conditional pair density respect to the marginal probability (χ X C ). As reported previously, χ X C, can be used to reveal the regions of the space associated to the classical electron pair model. Here, correlated wave-functions, such as CISD, MP2, and CCSD, are considered for the calculation ofχ X C . This is achieved by introducing an approximated method based on employing natural orbitals and their occupancy numbers. In addition toχ X C, in this work we propose a measure of the information content of the same-spin correlation hole, which is computed in terms of the Kullback–Leibler divergence of a correlated same-spin conditional pair density respect to the uncorrelated Hartree–Fock pair density (χ C ). The proposed methodology is discussed in the light of the result derived from noble gas atoms, theF 2 molecule and some non-covalently bonded systems. GRAPHICAL ABSTRACT: