文档介绍：From ASA Towards the Full Potential
J. Koll´ar1, L. Vitos1,2, and . Skriver3
1 Research Institute for Solid State Physics,
H-1525 Budapest, 49, Hungary
2 Condensed Matter Theory Group, Physics Department,
Uppsala University, S-75121 Uppsala, Sweden
3 Center for Atomic-scale Materials Physics and Department of Physics,
Technical University of Denmark, DK-2800 Lyngby, Denmark
Abstract. bine the simplicity and efficiency of atomic-sphere approxima-
tion (ASA) based electronic structure calculations and the accuracy of full potential
techniques, we have developed a full charge-density (FCD) method. In this method
the charge density is obtained from the output of self-consistent linear muffin-tin or-
bitals (LMTO) ASA calculations, the Coulomb energy is calculated exactly from the
complete, nonspherically symmetric charge density defined within nonoverlapping,
space-filling Wigner-Seitz cells, and the exchange-correlation energy is evaluated by
means of the local density approximation or the generalized gradient approxima-
tion applied to plete charge-density. The ic energy is obtained as the
ASA ic energy corrected for the nonspherically symmetric charge-density by
a gradient expansion. The integration over the Wigner-Seitz cell is carried out by
means of the shape truncation function technique, which is also discussed in detail.
The FCD technique retains most of the simplicity putational efficiency of
the LMTO-ASA method, while several tests for bulk metals and surfaces show that
the accuracy of the method is similar to that of full potential methods.
1 Introduction
As a consequence of the rapidly putational facilities followed
by the development puter codes, the ab initio electronic structure me-
thods are able to treat more and plicated problems, closely related
to applications, with sufficiently high accuracy. During the last two deca-
des the linear muffin-tin orbitals (LMTO) method [1,2,4,9,3,6,7,5,8] has been