Range-separated density-functional theory applied to the beryllium dimer and trimer
Résumé
The beryllium dimer and trimer are, despite their small number of electrons, excellent systems for assessing electronic-structure computational methods. With reference data provided by multi-reference averaged coupled-pair functional calculations, we assess several variants of range-separated density-functional theory, combining long-range second-order perturbation theory or coupled-cluster theory with a short-range density functional. The results show that i) long-range second-order perturbation theory is not sufficient, ii) long-range coupled-cluster theory gives reasonably accurate potential energy curves, but iii) provided a relatively large value of $\mu=1$ bohr$^{-1}$ for the range-separation
parameter is used. The article is dedicated to the memory of J\'anos G. \'Angy\'an.
Domaines
Chimie-Physique [physics.chem-ph]Origine | Fichiers produits par l'(les) auteur(s) |
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