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HL: Halbleiterphysik

HL 8: Theorie II

HL 8.8: Talk

Monday, March 17, 1997, 17:15–17:30, H2

Plane-wave band-structure methods without pseudopotentials — •F. Starrost, E.E. Krasovskii, and W. Schattke — Institut f"ur Theoretische Physik, Christian-Albrechts-Universit"at Kiel, Leibnizstr. 15, 24098 Kiel

We show that the concept of the extended linear methods of band theory yields a convenient plane-wave-based formalism for the ab initio treatment of the electronic structure. It leads to a computational scheme that combines the plane-wave representation of the wavefunctions with the efficiency of the linear methods in treating realistic singular crystal potentials. We present the formalism based on the exact ELAPW-k^→·p^→ method [1], which employs a single transfer matrix between the APW and the plane wave sets. Thus the matrix elements of the Hamiltonian operator are expressed in terms of the APW’s whereas the other quantities are expressed in terms of plane waves. Insofar as calculations of matrix elements of the singular potential and the Laplacian are not involved the number of plane waves can be reduced by orders of magnitude with respect to that in the pseudopotential calculations without considerable loss of accuracy. We study the applicability of the scheme to dielectric and ground state properties of transition metals and zinc-blende semiconductors. The scheme we propose enables one to avoid any ambiguity intrinsic to ab initio pseudopotentials and makes it possible to get better accuracy with less computational effort.

[1] E. E. Krasovskii, W. Schattke, Solid State Commun. 93, 775 (1995)