Hg199Knight shift and spin-lattice relaxation inHgBa2CuO4+δ

${}_{}{}^{199}{}_{}{}^{}\mathrm{Hg}$ NMR spectra and ${\mathit{T}}_1^{\mathrm{-}1}$ are reported for two samples of ${\mathrm{HgBa}}_2$ ${\mathrm{CuO}}_{4+\mathrm{\delta }}$ with superconducting transitions at ${\mathit{T}}_{\mathit{c}}$=95 K and ${\mathit{T}}_{\mathit{c}}$=80 K, respectively. The spectra are characteristic powder patterns with large anisotropic shifts: 3${\mathit{K}}_{\mathrm{ax}}$=-0.43% and -0.52%, respectively, for the two samples at room temperature with negligible temperature dependence below ${\mathit{T}}_{\mathit{c}}$. The isotropic Knight shifts were of order ${\mathit{K}}_{\mathrm{iso}}$=+0.11% with respect to a Hg(${\mathrm{NO}}_3$ ${)}_2$ aqueous solution. The relaxation rate is Korringa-like above ${\mathit{T}}_{\mathit{c}}$ while below ${\mathit{T}}_{\mathit{c}}$ the relaxation rate drops down exponentially without enhancement near ${\mathit{T}}_{\mathit{c}}$.