The Liu-Parr power series expansion of the Pauli kinetic energy functional with the incorporation of shell-inducing traits: Atoms

Eduardo V. Ludena, Edison X. Salazar*, Mauricio H. Cornejo, Dario E. Arroyo, Valentin V. Karasiev

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Abstract

An approximate expression for the Pauli kinetic energy functional T-p is advanced in terms of the Liu-Parr expansion [S. Liu, R.G. Parr, Phys. Rev. A1997, 55, 1792] which involves a power series of the one-electron density. We use this explicit functional for T-p to compute the value of the noninteracting kinetic energy functional T-s of 34 atoms, from Li to Kr (and their positive and negative monoions). In particular, we examine the effect that a shell-by-shell mean-square optimization of the expansion coefficients has on the kinetic energy values and explore the effect that the size of the expansion, given by the parameter n, has on the accuracy of the approximation. The results yield a mean absolute percent error abs=(1/N)for 34 neutral atoms of 0.15, 0.08, 0.04, 0.03, and 0.01 for expansions with n=3, 4, 5, 6, and 7, respectively (where i)). We show that these results, which are the most accurate ones obtained to date for the representation of the noninteracting kinetic energy functional, stem from the imposition of shell-inducing traits. We also compare these Liu-Parr functionals with the exact but nonexplicit functional generated in the local-scaling transformation version of DFT.

Original languageEnglish
Article number25601
Number of pages15
JournalInternational Journal of Quantum Chemistry
Volume118
Issue number14
DOIs
Publication statusPublished - 15-Jul-2018

Keywords

  • density functional theory
  • enhancement factor
  • kinetic energy functional
  • Kohn-Sham
  • Pauli functional
  • ORBITAL-FREE DFT
  • ELECTRON-DENSITY
  • GRADIENT EXPANSION
  • ENHANCEMENT FACTOR
  • EXCHANGE-ENERGY
  • TERMS
  • MOMENTS
  • APPROXIMATIONS
  • COMPONENTS
  • MOLECULES

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