The eutectic 7.3:2.7 molar ratio mixture of calcium and zinc metal melts at 394°C and was explored as a solvent for the growth of new intermetallic phases for potential use as hydrogen storage materials. The reaction of nickel in this molten mixture produces two new phases—the CaCu 5 -related structure CaNi 2 Zn 3 (P6/mmm, a=8.9814(5)Å, c=4.0665(5)Å) and a new cubic structure Ca 21 Ni 2 Zn 36 (Fd–3m, a=21.5051(4)Å). Palladium-containing reactions produced CaPd 0.85 Zn 1.15 with the orthorhombic TiNiSi structure type (Pnma, a=7.1728(9)Å, b=4.3949(5)Å, c=7.7430(9)Å). Reactions of platinum in the Ca/Zn mixture produce Ca 6 Pt 3 Zn 5 , with an orthorhombic structure related to that of W 3 CoB 3 (Pmmn, a=13.7339(9)Å, b=4.3907(3)Å, c=10.7894(7)Å).