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Influence of Coulomb-attenuation on exchange-correlation functional quality

Research output: Contribution to journalJournal article

Published

Journal publication date2006
JournalPhysical Chemistry Chemical Physics
Journal number39
Volume8
Number of pages7
Pages4543-4549
Original languageEnglish

Abstract

The dependence of functional quality on the attenuation parameters-which control the limiting (r(12) -> 0, infinity) values and the rate of attenuation-is investigated for a Coulomb-attenuated exchange-correlation functional. For the attenuation and functional form considered, satisfaction of an exact long-range condition is detrimental for properties such as atomisation energies and bond lengths, but does improve classical reaction barriers and small molecule electronic excitation energies. The functionals considered can provide high quality valence, Rydberg, intramolecular and asymptotic intermolecular charge transfer (CT) excitations, but none are able to provide a simultaneously optimal description of all classes; CT excitations are not necessarily improved compared to those from conventional functionals. The study highlights the need for further development of Coulomb-attenuated functionals.