Regarding real part of dielectric function

Regarding real part of dielectric function

Systemlabel.EPSIMG  generated by SIESTA, contains the imaginary part of the dielectric function in the energy range specified in the input file of SIESTA. the program The programs contained in the directory (siesta-2.0/Util/Optical) calculate different optical properties of a solid out of the file.

There are two small programs:

input.f

and

optical.f


Both can be compile independently:

     f77( f95, f90,....) input.f -o inpu
    
     f77( f95, f90,....)  optical.f -o optical


* The first program creates the input file for optical (e2.dat), containing the
imaginary part of the dielectric function, from the file Systemlabel.EPSIMG

* The second reads a file called 'e2.dat' containing
the imaginary part of the dieletric function, and creates the
files :
'epsilon_real.out'  containing the real part of the dielectric function
'epsilon_img.out'  containing the imaginary part of the dielectric function
'refrac_index.out'   containing the refraction index
'absorp_index.out'  containing the extintion coefficient
'absorp_coef.out'    containing the absorption coefficient in cm**-1
'reflectance.out'     containing the reflectance
'conductivity.out'     containing the optical conductivity in (ohm*m)**-1

To do so, you just need to type:

    ./ input < Systemlabel.EPSIMG
 
    ./optical
Karim