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The polarisability of atoms and molecules: a comparison between a conceptual density functional theory approach and time-dependent density functional theory |
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| Authors: | Zino Boisdenghien Stijn Fias Fabiana Da Pieve Frank De Proft Paul Geerlings |
| Institution: | 1. General Chemistry (ALGC), Vrije Universiteit Brussel (Free University Brussels – VUB) Brussel, Belgiumzboisden@vub.ac.be;3. General Chemistry (ALGC), Vrije Universiteit Brussel (Free University Brussels – VUB) Brussel, Belgium;4. European Theoretical Spectroscopy Facility (ETSF), Ecole Polytechnique, Palaiseau, France;5. Laboratoire des Solides Irradiés, Ecole Polytechnique, Palaiseau, France |
| Abstract: | We investigate the local polarisability or polarisability density using both a conceptual density functional theory approach based on the linear response function and time-dependent density functional theory. Using a zero frequency in the latter, we can immediately compare both approaches. Using an analytical expression for the linear response kernel, we are able to systematically analyse α(r) throughout the periodic table. An extension to molecules is also made with a study of the CO molecule retrieving the connection between local softness and local polarisability. |
| Keywords: | conceptual density functional theory time-dependent DFT linear response local polarisability atoms |