and G.A. RINKER Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA Received 19 August 1985
PROGRAM SUMMARY Title of subroutines: FD, FDG, FDH
Keywords: plasma physics, Fermi statistics, transport coefficients
Catalogue number: AADU Program obtainable from: CPC Program Library, Queen’s University of Belfast, N. Ireland (see application form in this issue) Computers: Cray-i, X-MP; Installation: Los Alamos National Laboratory
Nature of physical problem Generalized Fermi—Dirac integrals are evaluated. These integrals arise in applications of statistical mechanics to Fermi systems. Method of solution Chebyschev polynomial representations are provided.
Programming language used: Fortran 77 High speed storage required: 3084 words No. of bits in a word: 64 Peripheralrequired: output device for error messages No. of lines in combined program and test deck: 2119
Restriction The argument a can be any positive or negative real number. The indices ~s and v are restricted to certain half-integral values, as discussed in the text. Typical running times Average computation time is approximately 20 s s per evaluation on a Cray-i.
LONG WRITE-UP In the quantum-mechanical treatment of electrical and thermal transport in plasmas, one encounters integrals with the Fermi statistical weight [exp( t a) + 1] 1 The normal Fermi—Dirac integral is defined by —
F(a)=J
dt
______
o 1 + et~ This integral appears in many applications. Accurate and efficient rational approximations have been obtained by Cody and Thacher [1] for ~ = 1/2, 1/2 and 3/2. Implementations of series expansions have been published by Bañuelos et al. [2]. Two related integrals appear in the plasma transport theory of Lampe [3], which is exploited in other work [4,5]. The logarithmic Fermi—Dirac integral is defined by —
Generalized Fermi — Dirac integrals
the package. They should be reset for the local environment before use. Most systems provide more sophisticated error handling than does XERR, which can be replaced. Use of the routines The routines are defined by FD(v, a) = FDG(p, a)
=
FDH( i’,
a) = H~(a).
All arguments are real. Legal values of a are cc
—