Kohn-Sham potentials in exact density-functional theory at noninteger electron numbers
Résumé
Within exact electron density-functional theory, we investigate
Kohn-Sham (KS) potentials, orbital energies, and noninteracting
kinetic energies of the fractional ions of Li, C and F. We use quantum
Monte Carlo densities as input, which are then fitted, interpolated at
noninteger electron numbers N, and inverted to produce accurate KS
potentials v_s^N(r). We study the dependence of the KS potential
on N, and in particular we numerically reproduce
the theoretically predicted spatially constant discontinuity of
v_s^N(r) as N passes through an integer.
We further show that, for all the cases considered, the inner orbital
energies and the noninteracting kinetic energy are nearly piecewise
linear functions of N. This leads us to propose a simple
approximation of the KS potential v_s^N (r) at any fractional
electron number N which uses only quantities of the systems with the
adjacent integer electron numbers.
Origine | Fichiers produits par l'(les) auteur(s) |
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Origine | Fichiers produits par l'(les) auteur(s) |
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