Quantitative interpretations of scattering patterns from a charge-stabilized colloidal dispersion are described. The scattering patterns for a range of structural models based upon the stacking of layers of hexagonally arranged particles are calculated and compared with experimental data. Inclusion of both position and intensities is essential in this analysis to distinguish between the alternative structures. The structure appears to be most closely represented as layers of particles stacked in an hexagonally close packed sequence. This contrasts with the usual observations of cubic structures.