Program fege
This program calculates the fege model exchange potential for use as
a local approximatin to the exact exchange potential.
The freeelectron gas exchange (fege) potential is based on the formulation
of S. Hara, [J. Phys. Soc. Japan 22, 710 (1967)] and is an energy dependent local
approximation to the exchange interaction.
Input data records
iuang, iugrd, iuanrd, iuden, iufege
ecor
nengv, (engv(i), i = 1, nengv)
Definition of the input variables

iuang
 Input unit with angular grid information

iugrd
 Input unit with radial grid information

iuanrd
 Input unit with information about l cutoff regions

iuden
 Input unit with electron density

iufege
 Output unit with fege exchange potential

ecor
 Offset energy (in atomic units) used to compute the fege exchange potential.
This is usually taken to be the ionization potential of the molecule.

nengv
 Number of energies to read in and compute

engv(i)
 Scattering electron kinetic energy in eV