usage:
foptics22.00-62-x86_64 [-i fplooutput_imag_part_interband_eps] ...
	[-os suffix_for_output_files] [-h]  ...
	[-gamma gamma1 [gamma2 ... gamman]] ...
	[-omega omega1 [omega2 ... omegan]] ...
	[-skip nskip] [-nointer] [-nointra] [-ni]

fplooutput_imag_part_interband_eps: normally +imeps
omega: the plasmon frequencies for the intraband contributions in eV
gamma: the broadening (life time) for the intraband contributions in eV
nskip: take only every nskip data point 
-nointer: only take the intraband contributions
-nointra: only take the interband contributions
-ni = not interactively: take values from +plasmon and from -gamma and -omega
but do not ask for not explicitly specified values.

There are 3 gamma values: for each principal axis one.
There are 3 omega values along the principal axes for each spin direction
and for the total (spin sum). This is so, since the principal axes
need no coincide for spin up, spin down and the spin sum.
In non-spin-polarized cases ony spin1 is used and equals the spin sum.


This program reads inter-band output from FPLO (+imeps)
and calculates some optical functions. The user can define
plasmon frequencies and broadenings to include the intra-band
contributions.

The program also reads the file +plasmon to extract the calculated
plasmon energies and the principal axes of the plasmon tensor.
The user can overwrite the plasmon energies by interactive input
or by the option -omega.

The output functions are 
	re_eps: real part of epsilon
	im_eps: imaginary part of epsilon
	re_sigma: real part of the optical conductivity in inverse Ohm*cm
	loss: the loss function
For the individual spin contributions _spin1/_spin2 is appended to the 
file names. (Only for spin polarized cases.)
If an output suffix (-os) is defined it will be appended to all file names.




