The electronic structure of one- and two-dimensional cuprates from high-energy spectroscopy

We report studies of the electronic structure and elementary excitations of undoped, one- and two-dimensional cuprates. Using high-energy spectroscopi es such as X-ray absorption, photoemission and electron energy-loss spectro scopy, important information regarding the charge distribution, hole dynami cs and dielectric response has been obtained. The comparison of the experim ental data with suitable theoretical models sets constraints on the paramet ers entering into the model calculations. (C) 1999 Elsevier Science B.V. Al l rights reserved.