Accurate Kohn–Sham ionization potentials from scaled‐opposite‐spin second‐order optimized effective potential methods |
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| Authors: | Szymon ?miga Fabio Della Sala Adam Buksztel Ireneusz Grabowski Eduardo Fabiano |
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| Institution: | 1. Istituto Nanoscienze‐CNR, Euromediterranean Center for Nanomaterial Modelling and Technology (ECMT), Lecce;2. Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Torun, Poland;3. Center for Biomolecular Nanotechnologies @UNILE, Istituto Italiano Di Tecnologia, Arnesano, Italy |
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| Abstract: | One important property of Kohn–Sham (KS) density functional theory is the exact equality of the energy of the highest occupied KS orbital (HOMO) with the negative ionization potential of the system. This exact feature is out of reach for standard density‐dependent semilocal functionals. Conversely, accurate results can be obtained using orbital‐dependent functionals in the optimized effective potential (OEP) approach. In this article, we investigate the performance, in this context, of some advanced OEP methods, with special emphasis on the recently proposed scaled‐opposite‐spin OEP functional. Moreover, we analyze the impact of the so‐called HOMO condition on the final quality of the HOMO energy. Results are compared to reference data obtained at the CCSD(T) level of theory. © 2016 Wiley Periodicals, Inc. |
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| Keywords: | optimized effective potential method ionization potential spin component scaled method |
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