Self-consistent ab-initio electronic energy band structure of zinc blende CdS are reported within the local density functional (LDF) formalism. Our first principle, non-relativistic and ground state calculations employed a local density functional approximation (LDFA) potential and the linear combination of atomic orbitals (LCAO). Within the framework of the Bagayoko, Zhao, and Williams (BZW) method, we solved self-consistently both the Kohn-Sham equation and the equation giving the ground state density in terms of the wave functions of the occupied states. Our calculated, direct band gap of 2.39 eV, at the Γ point, is in accord with experiment. Our calculation reproduced the peaks in the conduction and valence bands density of states, within experimental uncertainties. So are the electron effective mass.

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We present results from ab-initio, self-consistent local density approximation (LDA) calculations of electronic and related properties of zinc blende indium phosphide (InP) and gallium phosphide (GaP) . We employed a LDA potential and implemented the linear combination of atomic orbitals (LCAO) formalism. This implementation followed the Bagayoko, Zhao and Williams (BZW) method, as enhanced by Ekuma and Franklin (BZW–EF). This method searches for the optimal basis set that yields the minima of the occupied energies. This search entails increases of the size of the basis set and the related modifications of angular symmetry and of radial orbitals. Our calculated, direct band gap of 1.398 eV (1.40 eV), at the Γ point, is in excellent agreement with experimental values, for InP , and our preliminary result for the indirect gap of GaP is 2.135 eV, from the Γ to X high symmetry points. We have also calculated electron and hole effective masses for both InP and GaP . These calculated properties also agree with experimental findings. We conclude that the BZW–EF method could be employed in calculations of electronic properties of high-Tc superconducting materials to explain their complex properties.

Abstract:The thermodynamics expected of systems undergoing third order phase transition has been investigated by identifying the orders through the analytic continuation of the functional of the free energy, using Ehrenfest thermodynamic theory. We developed the Euler -Lagrange equations for the order parameter and the vector potential and solved them for the first time using well -known mathematical formulations.

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