Relativistie Augmented Plane Wave Method

Abstract

AbstractThe relativistic augmented plane wave method for the determination of electronic energy eigenvalues in crystals is reformulated assuming that boththe upper and lower components of the trial wave functions are continuous at the Slater sphere. A variational expression for the energy, suitable for this kind of wave functions, is given and the matrix elements are evaluated. The resultant secular determinant is shown to be variational when the Dirac energy eigenvalue for the solution of the Dirac radial wave equations, with the atomic muffin‐tin potential within the Slater spheres, is equal to the crystal energy. The theory reduces, in the suitable limits, to that one formulated earlier by Loucks, who assumed that only the upper (large) components of the wave functions are matched leaving the lower (small) components discontinuous at the Slater spheres.