Abstract
Kohn-Sham density functional theory has been tremendously successful in chemistry and physics. Yet, it is unable to describe the energy degeneracy of spin-multiplet components with any approximate functional. This work features two contributions. (1) We present a multistate density functional theory (MSDFT) to represent spinmultiplet components and to determine multiplet energies. MSDFT is a hybrid approach, taking advantage of both wave function theory and density functional theory. Thus, the wave functions, electron densities and energy density-functionals for ground and excited states and for different components are treated on the same footing. The method is illustrated on valence excitations of atoms and molecules. (2) Importantly, a key result is that for cases in which the high-spin components can be determined separately by Kohn-Sham density functional theory, the transition density functional in MSDFT (which describes electronic coupling) can be defined rigorously. The numerical results may be explored to design and optimize transition density functionals for configuration coupling in multiconfigurational DFT.
Original language | English (US) |
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Pages (from-to) | 4838-4845 |
Number of pages | 8 |
Journal | Journal of Physical Chemistry Letters |
Volume | 8 |
Issue number | 19 |
DOIs | |
State | Published - Oct 5 2017 |
Bibliographical note
Funding Information:This work has been generously supported by the Ministry of Science and Technology of China (Grant number 2017YFB0203400), and the National Institutes of Health (GM46736).
Publisher Copyright:
© 2017 American Chemical Society.