A full-band FPLAPW+k⋅pFPLAPW+k⋅p-method for solving the Kohn–Sham equation

We have implemented a full-band k⋅pk⋅p-approach into a full-potential linearized augmented plane wave (FPLAPW) code in order to more efficiently—and still accurately—calculate the electronic and optical properties of periodic crystalline solids within the Kohn–Sham single-electron formalism. The validity of this full-band k⋅pk⋅p-method is discussed as well as the convergence of the eigenvalues and eigenvectors with respect to basis set and k-mesh, with applications to the semiconductor ZnO and the metal Al. Moreover, the accuracy of the FPLAPW+k⋅pFPLAPW+k⋅p-method for computing the band structure and the dielectric function is demonstrated for the more complex materials YBa2Cu3O7 and poly(para  -phenylene). For these structures, the full-band k⋅pk⋅p-approach reduces the computational time by as much as 90%.