Na or Ca, when dissolved in ammonia, yield metallic liquids. These liquids are fully miscible and yet each possesses a different intermediate-range order depending on the parent metal. Ca is a 'structure forming' core in Ca-NH3, possessing a sharply defined pre-peak in its structure factor. Na, on the other hand, is not and possesses no pre-peak until the highest possible concentrations of metal. This is surprising considering the similar cationic radii of Na+ and Ca2+, and the picture of the metal-ammonia solutions as core-like cations with a vast majority of the conduction electron density residing several angstroms from these cores. This study aims to determine the effect of being a tertiary system on intermediate-range structural correlations in Na-Ca-NH3, as dependant on the metal concentration and the concentration of conduction electrons.