Study of Structural and Electronic Properties of Alkaline Earth Metal Calcium and Strontium

Abstract

We optimize lattice parameter and identify the nature and values of band gap of Calcium and Strontium using quantum espresso. This piece includes the general introduction on crystal structure and different models that work in the lattice constant and lattice dynamic. We also attempt to briefly include various Theoretical details such as Born-Oppenheimer Approximation, Hartree-Fock Approximation, Density Functional Theory, Kohn-Sham approach, Local Density approximation, Generalized Gradient Approximation, and pseudo- potential. Finally, we discussed the fundamentals of Quantum Espresso computational program with the result and discussion on electronic properties, kinetic energy cut-off, lattice parameter, band gap, density of state and partial density of state.During optimization, the kinetic energy cut-off energy is found to be 90 Ry having k-point grid for Ca. Then we estimate the lattice Parameter is found to be 10.46 Bohr for Ca which is very near with experimental results as well as previous calculated data. Which is only 0.95 deviated from experimental result and previous data. Thus the lattice parameter of Ca estimated with GGA method is in close agreement with experimental values. Then we have study the band structure, density of states and partial density of states of Ca using GGA method in QE package.Similarly, optimization, the kinetic energy cut-off energy is found to be 110 Ry having k-point grid for Sr. Then we estimate the lattice Parameter is found to be 11.49 Bohr for Sr which is very near with experimental results as well as previous calculated data. Which is only 0.9 deviated from experimental result and previous data. Thus the lattice parameter of Sr estimated with GGA method is in close agreement with experimental values. Then we have study the band structure, density of states and partial density of states of Ca using GGA method in QE package.