Alternative Representations of the Correlation Energy in Density‐Functional Theory: A Kinetic‐Energy Based Adiabatic Connection. Issue 1 (18th September 2015)

• Record Type: Journal Article
• Authors: Teale, Andrew M.; Helgaker, Trygve; Savin, Andreas
• Is Part Of: Journal of the Chinese Chemical Society. Volume 63:Issue 1(2016:Jan.)
• Page Start: 121
• Page End: 128
• Publication Date: 2015-09-18
• Subjects: Density‐functional theory -- Adiabatic connection -- Correlation energy -- Coupled‐cluster theory -- Kohn‐Sham theory; Chemistry -- Periodicals; Electronic journals; 540.5
• DOI: 10.1002/jccs.201500132
• Languages: English
• ISSNs: 0009-4536

Abstract

Abstract: The adiabatic‐connection framework has been widely used to explore the properties of the correlation energy in density‐functional theory. The integrand in this formula may be expressed in terms of the electron–electron interactions directly, involving intrinsically two‐particle expectation values. Alternatively, it may be expressed in terms of the kinetic energy, involving only one‐particle quantities. In this work, we explore this alternative representation for the correlation energy and highlight some of its potential for the construction of new density functional approximations. The kinetic‐energy based integrand is effective in concentrating static correlation effects to the low interaction strength regime and approaches zero asymptotically, offering interesting new possibilities for modeling the correlation energy in density‐functional theory Abstract : A novel representation for the exchangecorrelation energy in KohnSham theory is investigated using ab initio methods. This approach places emphasis on the kinetic energy and the one‐particle reduced density matrix, providing a potentially fruitful perspective for the development of new approximations.