Analysis of NMR data on cuprate superconductors based on calculated hyperfine coupling energies

Spin susceptibilities are derived from measured spin shifts at the planar copper and oxygen sites in La 1.85Sr 0.15CuO 4 and YBa 2Cu 3O 7 using values for the nuclear hyperfine coupling parameters that have been obtained with the help of first-principles cluster calculations. The calculated hyperfine field at the oxygen site is effectively determined by just the two nearest neighbor copper ions which implies that the nuclei experience locally commensurate antiferromagnetic fluctuations. Therefore we have recalculated the temperature dependencies of the spin–lattice relaxation data.