Has a version
MgCu2 C15 Laves phase (Fd-3m) - relaxed
C15 Laves phase MgCu2, Fd-3m (#227), 24-atom conventional cell. Mg at 8a (1/8,1/8,1/8), Cu at 16d (0,0,1/2). Zero free Wyckoff parameters. Built for Wyckoff gradient discriminator test — metallic bonding at Fd-3m, same Laves AB2 topology as C14.