Relativistic formulation for the nuclear-spin-lattice relaxation rate in metallic systems: Applications to ${\mathrm{Ag}}_{\mathrm{x}}$${\mathrm{Pt}}_{1\mathrm{-}\mathrm{x}}$

The nuclear-spin-lattice relaxation rate ($T_1$T${)}^{\mathrm{-}1}$ in metallic systems is formulated in a relativistically correct form, which is applicable to pure metals as well as to alloys. As an example, the results of relativistic Korringa-Kohn-Rostoker coherent-potential approximation calculations for the alloy system ${\mathrm{Ag}}_{\mathrm{x}}$${\mathrm{Pt}}_{1\mathrm{-}\mathrm{x}}$ are used to calculate the relaxation rates of Ag and Pt in this system.