Understanding formation of the InPd3 polymorphs: a DFT study

Abstract The intriguing experimental results regarding the synthesis and structure types adopted by binary InPd3 have been fundamentally addressed using first-principles density functional theory calculations. Longer annealing time at higher temperature leads to stronger and more optimized heteroatomic In–Pd contacts that result in the extended ordering between them and leading to the ZrAl3 structure type. This is followed by another ordered derivative of the TiAl3-type and the metastable disordered AuCu-type when the annealing time and temperature were reduced. The thermodynamic stability order of these three polymorphs of InPd3, i.e. ZrAl3-type > TiAl3-type > AuCu-type is understood from the correlation between formation enthalpies, Madelung energies, and electronic structure and chemical bonding analysis.