Second-order adiabatic connection: The theory and application to two electrons in a parabolic confinement

Andreas Savin; Jacek Karwowski

doi:10.1063/5.0167851

Second-order adiabatic connection: The theory and application to two electrons in a parabolic confinement

J Chem Phys. 2023 Oct 7;159(13):134107. doi: 10.1063/5.0167851.

Authors

Andreas Savin¹, Jacek Karwowski²

Affiliations

¹ Laboratoire de Chimie Théorique, CNRS and Sorbonne University, 4 place Jussieu, 75252 Paris, France.
² Faculty of Physics, Astronomy and Informatics, Institute of Physics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Toruń, Poland.

PMID: 37791626
DOI: 10.1063/5.0167851

Abstract

The adiabatic connection formalism, usually based on the first-order perturbation theory, has been generalized to an arbitrary order. The generalization stems from the observation that the formalism can be derived from a properly arranged Taylor expansion. The second-order theory is developed in detail and applied to the description of two electrons in a parabolic confinement (harmonium). A significant improvement relative to the first-order theory has been obtained.