A multiconfigurational hybrid density-functional theory

Kamal Sharkas (1, 2) , Andreas Savin (1) , Hans Jørgen Aa. Jensen (3) , Julien Toulouse (1)

1 LCT - Laboratoire de chimie théorique
2 AECS - Atomic Energy Commission of Syria
3 Department of Physics, Chemistry, and Pharmacy

We propose a multiconfigurational hybrid density-functional theory which rigorously combines a multiconfiguration self-consistent-field calculation with a density-functional approximation based on a linear decomposition of the electron-electron interaction. This gives a straightforward extension of the usual hybrid approximations by essentially adding a fraction λ of exact static correlation in addition to the fraction λ of exact exchange. Test calculations on the cycloaddition reactions of ozone with ethylene or acetylene and the dissociation of diatomic molecules with the Perdew-Burke-Ernzerhof (PBE) and Becke-Lee-Yang-Parr (BLYP) density functionals show that a good value of λ is 0.25, as in the usual hybrid approximations. The results suggest that the proposed multiconfigurational hybrid approximations can improve over usual density-functional calculations for situations with strong static correlation effects.

Mots clés: density-functional theory; multiconfiguration self-consistent field; static correlation

Domaines: Chimie théorique et/ou physique; Chimie-Physique [physics.chem-ph]; Physique Numérique [physics.comp-ph]

Kamal Sharkas, Andreas Savin, Hans Jørgen Aa. Jensen, Julien Toulouse. A multiconfigurational hybrid density-functional theory. Journal of Chemical Physics, 2012, 137 (4), pp.044104. ⟨10.1063/1.4733672⟩. ⟨hal-00724033⟩