Input/Output files) indicates that the intrinsic yield of struvite precipitation was ~46% at the equilibrium. This means that the final aqueous solution was equilibrated with crystals at ~0.33% of the volume fraction (M w = 245.41 g/mol; d = 1.71 g/cm 3 ), which was sufficient to measure scattering patterns with an acceptable signal-to-noise ratio on our instrument (see below).