One more site-specific chemical substitution, followed by the ordering between the neighbouring elements (In and Pd) was explored by our group. In this particular case, Cu selectively chooses one of two different Pd-sites of TiAl3-type InPd3 and at the end composition , perfectly ordered InPd2Cu (I4/mmm, tI8, 139) is formed. The formation of perfectly ordered InPd2Cu is particularly noteworthy, as it suggests that the ordering may be driven by a combination of size, electronegativity, and valence electron concentration effects, as well as the crystal symmetry and bonding interactions. .