English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The equilibrium structure and exchange constants of CaMnO$_3$ and LaMnO$_3$have been investigated using total energy unrestricted Hartree-Fock (UHF) andlocalised orbital configuration interaction (CI) calculations on the bulkcompounds and Mn$_2$O$_{11}^{14-}$ and Mn$_2$O$_{11}^{16-}$ clusters. Thepredicted structure and exchange constants for CaMnO$_3$ are in reasonableagreement with estimates based on its N\'eel temperature. A series ofcalculations on LaMnO$_3$ in the cubic perovskite structure shows that aHamiltonian with independent orbital ordering and exchange terms accounts forthe total energies of cubic LaMnO$_3$ with various spin and orbital orderings.Computed exchange constants depend on orbital ordering. UHF calculations tendto underestimate exchange constants in LaMnO$_3$, but have the correct signwhen compared with values obtained by neutron scattering; exchange constantsobtained from CI calculations are in good agreement with neutron scatteringdata provided the Madelung potential of the cluster is appropriate. Cluster CIcalculations reveal a strong dependence of exchange constants on Mn d e$_g$orbital populations in both compounds. CI wave functions are analysed in orderto determine which exchange processes are important in exchange coupling inCaMnO$_3$ and LaMnO$_3$.Comment: 25 pages and 9 postscript figure

physical review. b, condensed matter

Exchange coupling in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">CaMnO</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">LaMnO</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mo>:</mml:mo></mml:…

Exchange coupling inCaMnO3andLaMnO3: