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arXiv · 0902.3559

Classes of admissible exchange-correlation density functionals for pure spin and angular momentum states

A. L. Tchougréeff·J. G. Ángyán
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Abstract

We analyze the various approaches to construct exchange-correlation functionals which are able to describe states of definite spin multiplicity in the DFT realm and outline the characteristics of possible functionals consistent with the Kohn-Sham theory. To achieve this goal the unitary group technique is applied to label many-electron states of definite total spin and to calculate the corresponding analogs of the Roothaan coupling coefficients. The possibility of using range separated Coulomb potential of electron-electron interaction for constructing functionals discriminating multiplet states in the d-shells is explored and a tentative system of state-specific functionals, covering nontrivial correlations in d-shells of transition metal ions, is proposed for the Fe^{2+} ions.

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A. L. Tchougréeff, J. G. Ángyán. 2009-02-20. Classes of admissible exchange-correlation density functionals for pure spin and angular momentum states. https://doi.org/10.1002/qua.22201

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