BORDAS , Esther

Quantum chemical calculations on embedded cluster models have been performed to extract accurate estimates of the magnetic coupling J and hopping parameters t of CaCu2O3. It is shown that this copper oxide compound is best described as a quasi-one-dimensional spin chain with weak interchain interactions within and between the Cu2O3 planes. This...

The four-spin cyclic exchange term Jring of three spin-ladder cuprates (SrCu2O3, Sr2Cu3O5, and CaCu2O3) has been calculated from ab initio quantum chemistry calculations. For the first two compounds, a non-negligible cyclic exchange is found, aproximately 20% of the magnetic coupling across the rungs, J⊥, and always larger than the value...