Geometrical optimization and the total energy calculation of the structural configurations were performed within the framework of Density Functional Theory (DFT), using the pseudopotential plane-wave self-consistent field software Quantum Espresso (QE) The ordered configurations of the TiAl3-type and the ZrAl3-type were directly adapted from their cif files available in Pearson Crystal Database . For the disordered AuCu type, an ordered 2 × 2 × 2 superstructure was built keeping the same stoichiometry (Fig. ). Under the generalized gradient approximation (GGA), developed in the Perdew-Burke-Ernzerhof (PBE) formalism, projector-augmented-wave (PAW) pseudopotentials were used . The kinetic energy cut-off was set to 500 and 50 Ry respectively for charge density and wave function. For geometrical optimization, k-point optimization test was performed and well-converged Monkhorst-Pack k-point meshes were applied to maintain an isotropic grid for reciprocal space integration for each case . The geometrical optimization and SCF calculations were performed with the 6 × 6 × 4 and 8 × 8 × 6 k-point mesh, respectively for the TiAl3-type and AuCu-type structure and 7 × 7 × 3 was applied for the ZrAl3-type structure. Volume-restricted cell relaxation during the geometrical optimization was performed with the Broyden-Fletcher-Goldforb-Shanno (BFGS) scheme. The density of states (DOS) and the crystal orbital Hamilton population (COHP) calculations were performed by implementing the LOBSTER program . Mulliken and Löwdin charge analysis were also performed from the wave functions using LOBSTER . The absolute charge spilling was found to be less than ~2% for all these calculations. DIAMOND 3 , VESTA , and wxDragon [41] were used for all structural figures and DOS and COHP plots respectively.