The structural investigations using structure prediction programs or requiring crystal engineering as here, need quantitative support from quantum mechanical calculations. Such investigations are mostly carried out within the framework of DFT , which is widely accepted by the scientific community. Briefly, the DFT was developed in two works: for the theoretical framework by Hohenberg and Kohn in 1964 , then followed by Kohn and Sham in 1965 , who established the Kohn-Sham equations for solving the wave equation practically within computational codes built around the DFT. The Vienna Ab initio Simulation Package (VASP) code and the Projector Augmented Wave (PAW) method for the atomic potentials were used for the identification of the ground state structures corresponding to the energy minima and the subsequent prediction of their mechanical and dynamical properties. DFT exchange-correlation (XC) effects were taken into account using the generalized gradient approximation (GGA) . Relaxation of the atoms to the ground state structures was performed with the conjugate gradient algorithm according to Press et al. . The Blöchl tetrahedron method with corrections according to the Methfessel and Paxton scheme was used for geometry optimization and energy calculations, respectively. Brillouin-zone (BZ) integrals were approximated by a special k-point sampling according to Monkhorst and Pack . Structural parameters were optimized until atomic forces were below 0.02 eV/Å and all stress components were < 0.003 eV/Å 3 . The calculations were converged at an energy cutoff of 400 eV for the plane-wave basis set in terms of the k-point integration in the reciprocal space from kx(6)×ky( )×kz up to kx ×ky ×kz to obtain a final convergence and relaxation to zero strains for the original stoichiometries presented in this work. In the post-processing of the ground state electronic structures, the charge density projections were operated on the lattice sites.