文档介绍：A Full-Potential LMTO Method
Based on Smooth Hankel Functions
M. Methfessel1, M. van Schilfgaarde2, and R. A. Casali3
1 Institute for Semiconductor Physics, Walter-Korsing-Str. 2, D-15230 Frankfurt
(Oder), Germany
2 SRI International, 333 Ravenswood Avenue, Menlo Park, California 94025
(Present Address: Sandia National Laboratories, Livermore, California 94551)
3 Department of Physics, Universidad Nacional del Nordeste, 3400 Corrientes,
Argentina
Abstract. The paper presents a recently developed full-potential linear muffin-tin or-
bital (FP-LMTO) method which does not require empty spheres and can calculate
the forces accurately. Similar to previous approaches, this method uses numerical in-
tegration to calculate the matrix elements for the interstitial potential, which is the
limiting step for any FP-LMTO approach. However, in order to reduce the numerical
effort as far as possible, we use a newly introduced basis consisting of “augmented
smooth Hankel functions” which play the role of the LMTO envelope functions. After
presenting the basics of the approach, we report the results of numerical test for typical
condensed-matter systems. The calculations show that good accuracy can be reached
with an almost minimal basis set. These features of the method open the way to ef-
ficient molecular dynamics studies and simulated-annealing calculations to optimize
structures while retaining the advantages of the LMTO method.
1 Introduction
The linear muffin-tin orbital (LMTO)method [1] has played a very essful
role among the various techniques for solving the density-functional equations [2]
for a condensed-matter system. Two characteristic features of this approach are
(i)the use of atom-centered basis functions of well-defined angular momentum,
constructed out of Hankel functions, and (ii)the use of augmentation to in-
troduce atomic detail into the basis functions in the vicinity of each nucleus.
Overall, the rationale beh