Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Springer eBooks

Theoretical Ab-Initio Approach of Exchange Coupling in Weakly Interacting Dimers

Jean Pierre Daudey, Philippe De Loth, Jean‐Paul Malrieu

Published Jan 1, 1985• 12 citations
Publisher
DOI
10.1007/978-94-009-6511-9_4

Related papers

Europium dimer: van der Waals molecule with extremely weak antiferromagnetic spin coupling

Alexei A. Buchachenko, Grzegorz Chałasiński, Małgorzata M. Szczęśniak

High-level ab initio calculations reveal that the Eu(2) dimer is a van der Waals molecule with extremely weak antiferromagnetic spin coupling. The Heisenberg spin-exchange model, validated by the multireference configuration interaction method, is used to construct the full set of model interaction potentials for the states with the total spin S ranging from 0 to 7 at the coupled cluster level of theory. This model establishes the singlet (1) summation operator(+) (g) state as the ground one of the dimer with the binding energy of 710 cm(-1), the vibrational frequency of 23 cm(-1) and the effective spin-coupling constant J estimated approximately -0.3 cm(-1).

The Journal of Chemical Physics•Dec 28, 2009•16 citations

Theoretical studies of strongly correlated electronic systems

Hong Yao

•Jan 1, 2009•0 citations

Electronic and magnetic properties of small one-dimensional Wigner crystals from an ab initio approach

Daniele Lagasco, J. A. Berger

We present an \emph{ab initio} method to study the electronic and magnetic properties of small one-dimensional Wigner crystals. In particular, we focus on the calculation of the electronic charge distribution and the exchange coupling constant. Our theoretical studies are motivated by the experimental observation of few-electron Wigner crystals in a carbon nanotube [Science 364, 870 (2019)]. We model the experimental setup by confining electrons in a one-dimensional potential well with infinite side barriers. We represent the Hamiltonian of the system in a basis of Slater determinants and perform full configuration interaction to ensure we capture all the electron correlation for a given basis set. As the one-particle basis set we use particle-in-a-box wave functions which by construction satisfy the boundary conditions. With our approach, we obtain accurate electronic density profiles of small one-dimensional Wigner crystals. These profiles clearly show the localisation of the electrons. Finally, we present a simple approach to obtain the exchange coupling constant by mapping our \textit{ab initio} method on a Heisenberg Hamiltonian. We illustrate our approach on a Wigner dimer. We obtain excellent agreement with a result in the literature.

arXiv:2607.26858•Jul 29, 2026•0 citations

Phase transition in an 1D interacting dimers: An exact and simulational study

L. S. Ferreira, L. N. Jorge, Minos A. Neto +1 more

Chemical Physics•Jan 15, 2022•0 citations

A study of exchange interactions in alkali molecular ion dimers with application to charge transfer in cold Cs

Michael J. Jamieson, A. Dalgarno, M Aymar +1 more

The formulation of Bardsley et al (Phys. Rev. A 11 1911) for evaluating the asymptotic electron exchange interaction between an alkali ion and its parent atom is extended by the use of a more accurate representation of the asymptotic wavefunction of the isolated atom and also by the inclusion of a further term in the series that accounts for the presence of the ion. The Bardsley analysis is compared with a purely numerical approach in which the Holstein–Herring integrand is constructed from a polarized wavefunction built from numerical solutions of the differential equations of Rayleigh–Schrodinger perturbation theory and the ¨ required quadrature is performed numerically. Values of the asymptotic exchange interactions are given for the molecular ions Li+ 2 , Na+ 2 , K+ 2 , Rb+ 2 and Cs+ 2 . As an example, exchange interactions for Cs+ 2 evaluated by an ab initio method are compared to those predicted by the Bardsley formula. Potentials for the lowest states of Cs+ 2 are constructed from the ab initio values matched to the asymptotic exchange and long-range polarization interactions, and these potentials are used to predict the 12+ g and 12+ u scattering lengths and low-energy charge transfer cross sections.

Journal of Physics B Atomic Molecular and Optical Physics•Apr 21, 2009•16 citations

Ab-initio Approaches to Correlated Materials

Harrison LaBollita

Springer theses•Jan 1, 2024•0 citations
High-level ab initio calculations reveal that the Eu(2) dimer is a van der Waals molecule with extremely weak antiferromagnetic spin coupling. The Heisenberg spin-exchange model, validated by the multireference configuration interaction method, is used to construct the full set of model interaction potentials for the states with the total spin S ranging from 0 to 7 at the coupled cluster level of theory. This model establishes the singlet (1) summation operator(+) (g) state as the ground one of the dimer with the binding energy of 710 cm(-1), the vibrational frequency of 23 cm(-1) and the effective spin-coupling constant J estimated approximately -0.3 cm(-1).
We present an \emph{ab initio} method to study the electronic and magnetic properties of small one-dimensional Wigner crystals. In particular, we focus on the calculation of the electronic charge distribution and the exchange coupling constant. Our theoretical studies are motivated by the experimental observation of few-electron Wigner crystals in a carbon nanotube [Science 364, 870 (2019)]. We model the experimental setup by confining electrons in a one-dimensional potential well with infinite side barriers. We represent the Hamiltonian of the system in a basis of Slater determinants and perform full configuration interaction to ensure we capture all the electron correlation for a given basis set. As the one-particle basis set we use particle-in-a-box wave functions which by construction satisfy the boundary conditions. With our approach, we obtain accurate electronic density profiles of small one-dimensional Wigner crystals. These profiles clearly show the localisation of the electrons. Finally, we present a simple approach to obtain the exchange coupling constant by mapping our \textit{ab initio} method on a Heisenberg Hamiltonian. We illustrate our approach on a Wigner dimer. We obtain excellent agreement with a result in the literature.
The formulation of Bardsley et al (Phys. Rev. A 11 1911) for evaluating the asymptotic electron exchange interaction between an alkali ion and its parent atom is extended by the use of a more accurate representation of the asymptotic wavefunction of the isolated atom and also by the inclusion of a further term in the series that accounts for the presence of the ion. The Bardsley analysis is compared with a purely numerical approach in which the Holstein–Herring integrand is constructed from a polarized wavefunction built from numerical solutions of the differential equations of Rayleigh–Schrodinger perturbation theory and the ¨ required quadrature is performed numerically. Values of the asymptotic exchange interactions are given for the molecular ions Li+ 2 , Na+ 2 , K+ 2 , Rb+ 2 and Cs+ 2 . As an example, exchange interactions for Cs+ 2 evaluated by an ab initio method are compared to those predicted by the Bardsley formula. Potentials for the lowest states of Cs+ 2 are constructed from the ab initio values matched to the asymptotic exchange and long-range polarization interactions, and these potentials are used to predict the 12+ g and 12+ u scattering lengths and low-energy charge transfer cross sections.