Solid mass fractions of solid planetary building blocks formed exterior to the water ice line as function of [Fe/H] where 20% of the C/H is assumed to be in carbon chains with an evaporation temperature of 500 K and only 25% of the C/H is assumed to be bound in CO. The trend for H₂O is similar toFig. 10. However, the water ice abundance at large [Fe/H] is about a factor of 2–3 larger, while it stays roughly constant for low [Fe/H] compared to the nominal chemical model (Fig. 10).