CDROM/APJS/V105/P407 Fermi-Dirac Integrals and Derivatives (Miralles+ 1996) ================================================================================ Accurate Evaluation of Fermi-Dirac Integrals and Their Derivatives for Arbitrary Degeneracy and Relativity Juan Antonio Miralles and Kenneth A. Van Riper <1996, ApJS, 105, 407> =1996ApJS..105..407M ================================================================================ Abstract: The equation of state of an ideal Fermi gas is expressed in terms of Fermi-Dirac integrals. We give formulae for evaluation the Fermi-Dirac integrals of orders 1/2, 3/2, and 5/2 and their derivatives in various limits of non- and extreme degeneracy and relativity. We provide tables and a FORTRAN subroutine for numerical evaluation in the integrals and derivatives when a limit does not apply. The functions can be evaluated to better than 1% accuracy for any temperature and density using these methods. Keywords: dense matter -- equation of state -- relativity -- stars: neutron Description: Three tables of integrals accompany this paper. The file fdints.tab contains the Fermi-Dirac integrals and the Fermi integrals. The file dfdints.tab contains the derivatives of the Fermi-Dirac and of the Fermi integrals. The Bessel functions are found in bessel.tab. The file fermi7h.tab contains the Fermi integrals of order 7/2. These tables are read by FORTRAN subroutine calcdfi, which is also provided along with the tables; the exact format of the tables can be found by examining the relevant READ statements in the subroutine. The functions and the derivatives are maintained as separate files to facilitate implementations where only the function values are required; subroutine calcfi, also supplied, is a variant of calcdfi with the derivatives stripped out. Subroutine calcdfi reads the data from the binary (or unformatted) files fdints.unf (which contains the Bessel data) and dfdints.unf if they both exist; if they do not exist, the formatted files fdints.tab, ... are read, and the logarithm of the data are written to binary files. The binary files are preferred because the formatted files are 5 times as large and take 35 times longer to load. All data is held in memory as (natural) logarithms. Note: See the author-supplied README file for details on compiling and installing the FORTRAN programs. File Summary: -------------------------------------------------------------------------------- File Name Lrecl Records Explanations -------------------------------------------------------------------------------- bessel.tab 40 59 Bessel functions dfdints.tab 112 1088 Derivatives of Fermi-Dirac and Fermi integrals fermi7h.tab 24 101 Fermi integrals of order 7/2 fdints.tab 104 1088 Fermi-Dirac and Fermi integrals Makefile 73 33 Makefile for FORTRAN programs README 72 104 Author-supplied description besscheb.f 75 240 Author-supplied FORTRAN source code calcdfi.f 73 740 Author-supplied FORTRAN source code calcfi.f 73 511 Author-supplied FORTRAN source code fdeos.f 72 174 Author-supplied FORTRAN source code fdstitch.f 72 222 Author-supplied FORTRAN source code polyint.f 71 74 Author-supplied FORTRAN source code -------------------------------------------------------------------------------- ================================================================================ (End) Lee Brotzman [ADS] 13-Aug-96