The electronic structure of CaCuO₂and SrCuO₂

Abstract

We have calculated and compared the electronic structures of both the 1D CuO-chain compound SrCuO2 and the 2D CuO2-plane material CaCuO2, on the basis of the local-spin-density approximation (LSDA) and the on-site Coulomb interaction correction (LSDA+U). The LSDA calculation gives a nonmagnetic and metallic solution as usual for CaCuO2, while it yields an antiferromagnetic (AFM) and insulating one for SrCuO2 due to the decreasing pd hybridization and the subsequent spin polarization with lowering dimensionality. Strongly in favour of orbital and spin polarizations of the Cu 3d states, the U interaction dominates in forming the charge transfer insulating character of both of the AFM cuprates. Some of the differences between the electronic structures can be qualitatively accounted for by the variance of dimensionality.

Comment on `The electronic structure of CaCuO2and SrCuO2'

“…The reason for the large discrepancy between the DOS of Ref. [1] and our's is evident from Figs. 1(c) and 1(d).…”

“…The authors of Ref. [1] claim that on the basis of their full-potential band structure experimental findings can be well fit with an U of 5 eV, significantly smaller than U values reported in previous calculations [3].…”

“…Considering the bands in Ref. [1] one realizes the following points: The authors show a bandstructure with orthorhombic symmetry for the tetragonal crystal structure [9] (note the different dispersions in Fig. 1(a) of Ref.…”

“…al. [1] presented bandstructure calculations for the quasi onedimensional CuO-chain compound SrCuO 2 and the quasi two-dimensional material CaCuO 2 , both being of prototypical character and therefore of general interest. Wu et.…”

“…1(a) of Ref. [1] along the Γ-(100) and Γ-(010) direction, respectively, which must be equivalent for the tetragonal case). Also, the band degeneracies at symmetry points are incorrect.…”