文档介绍：Excited States Calculated by Means of the
Linear Muffin-Tin Orbital Method
M. Alouani1 and J. M. Wills2
1 IPCMS, Universit´e Louis Pasteur, 23 Rue du Loess, 67037 Strasbourg, France
2 Los Alamos National Laboratory, Los Alamos, NM 87545, USA
Abstract. The most popular electronic structure method, the linear muffin-tin orbital
method (LMTO), in its full-potential (FP) and relativistic forms has been extended
to calculate the spectroscopic properties of materials form first principles, , optical
spectra, x-ray ic circular dichroism (XMCD) and o-optical kerr effect
(MOKE). The paper describes an overview of the FP-LMTO basis set and the calcula-
tion of the momentum matrix elements. Some applications concerning putation
of opticalproperties of semiconductors and XMCD spectra of transition metalalloys
are reviewed.
1 Introduction
The density functional theory (DFT) of Hohenberg, Kohn, and Shamis the
method of choice for describing the ground-state properties of materials [1].
However, in the initial derivation of the DFT, the eigenvalues are Lagrange mul-
tipliers introduced to orthogonalize the eigenvectors, which in their turn are
used pute the total energy and the charge density. In this formulation
the eigenvalues have therefore no physical meaning and should not be conside-
red as excited states. Nevertheless, the DFT in the local density approximation
(LDA) or in its spin resolved local density formulation (LSDA), has been used
essfully pute the excited states, namely, optical and o-optical
properties, x-ray absorption and ic dichroism spectra.
The LDA or LSDA were indeed intended pute the ground-state pro-
perties of materials, and their use during the last two decades has produced an
excellent track record in putation of these properties for a wide variety of
materials, ranging from simple metals plex semiconductor superlattices.
However, it is now believed that the DFT can do more puting the gro-
und state