Specific CI calculation of energy differences: Transition energies and bond energies

Miralles, Josefa; Castell, O.; Caballol, Rosa; Malrieu, Jean‐Paul

doi:10.1016/0301-0104(93)80104-h

Cited by 436 publications

(382 citation statements)

References 55 publications

Supporting

Mentioning

377

Contrasting

Order By: Relevance

“…The accuracy of each approach is established by comparison to experiment and/or ab initio calculations using highly sophisticated wave function methods. The wave function methods chosen in the present study are complete active space configuration interaction (CASCI), complete active space self consistent field (CASSCF) and difference dedicated configuration interaction (DDCI) [80,81]. These wave function based methods have been extensively used to describe magnetic coupling in a broad family of compounds and whenever experimental data is available the calculated results are all in the experimental range [79].…”

Section: Results and Discussion On Selected Numerical Examplesmentioning

confidence: 99%

Spin Symmetry Requirements in Density Functional Theory: The Proper Way to Predict Magnetic Coupling Constants in Molecules and Solids

et al. 2006

View full text Add to dashboard Cite

Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Abstract In this paper it is argued that the use of density functional theory (DFT) to solve the exact, non-relativistic, many-electron problem, for magnetic systems requires imposing space and spin symmetry constraints exactly in the same way as it is currently done in ab initio wave function theory. This strong statement is supported on pertinent calculations for selected systems representative of organic diradicals, molecular magnets and antiferromagnetic solids. These calculations include several wave function methods of increasing accuracy and different forms of the exchangecorrelation functional. The comparisons of numerical results carried out always within the same standard Gaussian Type Orbital atomic basis set show that imposing or not the spin and space constraints (restricted or unrestricted formalisms) leads to contradictory results. Therefore, it appears that, in the case of the Heisenberg magnetic constant, the present exchange-correlation functionals may provide reasonable numerical results although for the wrong physical reasons thus evidencing the failure of the current DFT methods to properly describe magnetic systems.

show abstract

Section: Results and Discussion On Selected Numerical Examplesmentioning

confidence: 99%

Spin Symmetry Requirements in Density Functional Theory: The Proper Way to Predict Magnetic Coupling Constants in Molecules and Solids

et al. 2006

View full text Add to dashboard Cite

show abstract

“…23,24 To find out if any deviations for a not strictly degenerate reference space ͑the CASCI reference space͒ can be observed, the effect of determinants with two degrees of freedom ͑MP2-2͒, three degrees of freedom ͑MP2-3͒, and four degrees of freedom ͑full MP2͒ was investigated within the perturbational approach.…”

Section: Methodsmentioning

confidence: 99%

On the magnetic coupling in NiO

Graaf

Illas

Broer

et al. 1997

The Journal of Chemical Physics

View full text Add to dashboard Cite

The results are reported of ab initio calculations on the magnetic ordering in NiO, a prototype of the antiferromagnetic insulator. By analyzing wave functions for different cluster models, information is obtained about the physical effects determining the sign and the magnitude of the magnetic coupling parameter J. The role of the edge oxygens, surrounding the essential unit ͑Ni 2 O͒, is found to be quantitatively important but purely environmental in contrast to the role of the bridging oxygen. Furthermore, the importance of electron correlation and the usefulness of pseudopotentials in the calculations is investigated. The final result for J compares reasonably with experiment ͑about 50%͒, and possible sources for the remaining discrepancies are discussed.

show abstract

“…After the study of coordination complexes of carbon dioxide and copper or molybdenum, [21,22] Rosa Caballol moved to binuclear complexes and the magnetic coupling research line emerged. [23][24][25] Simultaneously, to these more applied investigations, she got involved in the development of new algorithms and accurate quantum chemical methods. Important contributions were made to the development of efficient truncated or full CI programs [26,27] and the correction for size-consistency errors in of truncated MR-CI approaches.…”

Section: Moving To Ab Initio Calculationsmentioning

confidence: 99%

“…Broer and Maaskant performed such variational calculation when they analyzed the magnetic coupling in [Cu 2 Cl 6 ] 22 , [42] and performed in this way one of the first DDCI calculations, but the method was put on a firm basis a couple of years later by Miralles et al [23,24] In the first article, the degenerate reference space was analyzed and in the second one, the method was generalized to the nondegenerate case.…”

Section: Difference Dedicated Configuration Interactionmentioning

confidence: 99%

Methods for describing open-shell systems: Following the trail of Rosa Caballol's research

Graaf

Reguero

2014

Int. J. Quantum Chem.

View full text Add to dashboard Cite

On the occasion of the celebration of Prof. Rosa Caballol's 65's birthday, a symposium was organized by the Quantum Chemistry Group of the Universitat Rovira i Virgili (Tarragona, Spain) under the title "Theoretical Chemistry in Spain told by women." The symposium gave a representative illustration of the research in theoretical chemistry in Spain, which is not only very diverse, but also in many areas at the forefront of the field. In this article, we summarize the contributions made by Rosa Caballol and coworkers. Emphasis lies on the developments of wave function based methods to accurately describe electron correlation effects in systems with unpaired electrons. Besides discussing some illustrative applications, we will also explore the limits of the existing methods and outline the perspectives of how one can possibly overcome them.

show abstract

Specific CI calculation of energy differences: Transition energies and bond energies

Cited by 436 publications

References 55 publications

Spin Symmetry Requirements in Density Functional Theory: The Proper Way to Predict Magnetic Coupling Constants in Molecules and Solids

Spin Symmetry Requirements in Density Functional Theory: The Proper Way to Predict Magnetic Coupling Constants in Molecules and Solids

On the magnetic coupling in NiO

Methods for describing open-shell systems: Following the trail of Rosa Caballol's research

Contact Info

Product

Resources

About