  We report measurements of the evolution of the diffuse scattering in a single
crystal PbMg1/3Nb2/3O3 as a function of hydrostatic pressure. Upon applying
pressure the diffuse scattering intensity decreases and is suppressed at about
3 GPa, while no change in the line shape is observed. Correlations between Pb
displacements, diffuse scattering and relaxor properties are discussed.
