Density Functional Study of Mechanical, Electronic and Pressure Induced Phase Transition Properties of CaFé<sub>2</sub>As<sub>2</sub>

We report results on the ab initio study of mechanical and electronic properties iron Pnictide compound CaFe2As2 its phase transition under pressure using Quantum Espresso code. do analysis strength bonds in individual points this material proper Cauchy calculation which will give more insight elastic responses. Ground state energy was done framework density functional theory (DFT) based plane wave self-consistent field (PWscf) ultrasoft pseudo potential (USPP) method as treated Perdew-Burke Ernzerhof (PBE) generalized gradient approximation local approximations. Elastic constants were computed thermo_pw values used to calculate changes. From non-zero positive constants, Iron is found be mechanically stable Poisson’s ratio indicates that it brittle isotropic. Pressure induced here happen at an applied external 0.2 GPa causing tetragonal change orthorhombic agrees well with previous reports.