Influence of the Coulomb parameter U on partial densities of states of CuGeO<InlineEquation ID="Equ1"> <EquationSource Format="TEX">$_\mathsf{3}$</EquationSource> </InlineEquation>: comparison with X-ray spectral data

The electronic structure of the strongly Coulomb correlated cuprate CuGeO<Subscript>3</Subscript> has been calculated by the local-density-approximation method (LDA + U). The parameter U was varied from 0 to 8 eV. The results of the band-structure calculations are compared with experimental data obtained by means of X-ray photoelectron and resonant X-ray emission spectroscopy methods (Cu L<InlineEquation ID="Equ2"> <EquationSource Format="TEX">$\alpha$</EquationSource> </InlineEquation> and O K<InlineEquation ID="Equ3"> <EquationSource Format="TEX">$\alpha$</EquationSource> </InlineEquation> X-ray emission spectra). It is established that a LDA + U calculation with U=4 eV reproduces well the X-ray photoelectron and X-ray resonant emission spectral data. Copyright Springer-Verlag Berlin/Heidelberg 2004