Change search
ReferencesLink to record
Permanent link

Direct link
Ab initio study of exchange coupling for the consistent understanding of the magnetic ordering at room temperature in V[TCNE] (x)
KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
Show others and affiliations
2014 (English)In: Theoretical Chemistry accounts, ISSN 1432-881X, E-ISSN 1432-2234, Vol. 133, no 5, 1470- p.Article in journal (Refereed) Published
Abstract [en]

We report quantum chemical calculations providing the exchange coupling constants of the V[TCNE](2) model system, describing the amorphous room temperature molecular magnet V[TCNE] (x) (TCNE = tetracyanoethylene, x similar to 2). The geometry is optimized for the ideal lattice using density functional theory (DFT) calculations with periodic boundary conditions. Broken-symmetry DFT calculations indicate antiparallel spin alignment resulting in ferrimagnetic ordering, but heavily overestimate the value of the exchange coupling. Better estimates of the exchange coupling parameters between the V(II) ion and the [TCNE](-) anionic radical are obtained by means of multiconfigurational calculations performed on smaller molecular models cut from the optimized crystal lattice. Complete active space self-consistent field and multireference second-order perturbation theory calculations provide the sign and the strength of the nearest-neighbor as well as next-nearest-neighbor interactions along all three crystallographic directions. We are able to explain also intuitively the mechanism for antiferromagnetic spin coupling in terms of the superexchange pathways, discussing the role of the main four types of contributions to superexchange. Moreover, we clarify the influence of the transition metal ion on the strength of the exchange interaction and on the critical temperature for long-range ferrimagnetic ordering.

Place, publisher, year, edition, pages
2014. Vol. 133, no 5, 1470- p.
Keyword [en]
Molecular magnetism, Exchange coupling, CASSCF, MRPT2, DFT, Broken symmetry
National Category
Chemical Sciences
URN: urn:nbn:se:kth:diva-144365DOI: 10.1007/s00214-014-1470-0ISI: 000333032400001ScopusID: 2-s2.0-84899990511OAI: diva2:713323

QC 20140422

Available from: 2014-04-22 Created: 2014-04-22 Last updated: 2014-04-22Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Frecus, Bogdan
By organisation
Theoretical Chemistry and Biology
In the same journal
Theoretical Chemistry accounts
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 29 hits
ReferencesLink to record
Permanent link

Direct link