BAND PICTURE OF THE SPIN-PEIERLS CUPRATE CUGEO3

The electronic structure for the cuprate ${\mathrm{CuGeO}}_{3}$ has been studied by the generalization of the local-density-approximation method for the systems with strong Coulomb correlations. The stable insulating antiferromagnetic solution with an energy gap of $\ensuremath{\sim}3.02\mathrm{eV}$ and a magnetic moment of $0.89{\ensuremath{\mu}}_{B}$ is obtained. According to our results the strong copper on-site Coulomb interaction of $U=9.66\mathrm{eV}$ is the most important quantity for the gap opening in this inorganic spin-Peierls compound.