Doppler spectroscopy of core electrons is used to obtain information about the composition of silver-rich precipitates in (Al) under bar -Ag. Two-dimensional annihilation spectra were recorded both for elemental Al and Ag and for an A1-6at. %Ag alloy. Experimental data are compared with calculations based on density functional theory using the generalized gradient approximation (GGA) for the positron annihilation. In accordance with earlier work positron trapping at precipitates could be found. A qualitative comparison of the experimental and theoretical momentum distributions and the quantitative analysis by means of line shape parameters enables the determination of the composition of the precipitates.