NUCLEAR-QUADRUPOLE RESONANCE-SPECTRUM OF LA2CUO4

I report the results of ab initio quantum chemistry calculations addressing the nuclear quadrupole resonance (NQR) spectra of hole-doped La2CuO4. The experimental spectra point to two Cu environments, with a main peak, corresponding to a predominantly d(9) Cu site, and a satellite at similar to 3 MHz higher frequency. The cluster calculations exhibit broken-symmetry solutions in which an additional hole localizes on a single CuO6 unit, and predict a satellite in the NQR spectrum 2.7 MHz above the main peak. The satellite corresponds to Cu sites neighboring a localized hole. I conclude that some (similar to 25%) of the holes doped in to La2-xSrxCuO4 are localized on the NQR time scale of similar to 1 mu sec.