Investigation of Electronic and Structure Properties of MgB2 Superconductor by Ab-initio Method

The structural of MgB2 such as lattice constant, volume modulus, volume modulus derivative and compressibility of different degrees have been calculated. The calculations have been performed using a Full Potential-Linearized Augmented Plane Wave (FP-LAPW) method in the framework of Density Functional Theory (DFT) with various Approximation. The results show that the linear compressibility in direction of c is about twice the compressibility in direction of a. In addition, the electronic properties of the compound, including the structure of the energy bands, the density of the states, and the types of bonds in the MgB2 Superconductivity have been studied. The results of a double degeneracy above the Fermi level show that it plays an important role in the superconducting property. According to energy bands, it has been determined that the lattice parameters have a large effect on the s band of boron atoms. The results predict that the constant increase of the lattice along the c-axis has an increase in the density of states at the Fermi level. The results express this fact that the calculation using by GGA has the better agreements with the other theoretical and experimental approximations