The functionality suffers from some program bugs.
The revised code will be released in future.
The optical conductivity can be evaluated within linear response theory
OpenMX Ver. 3.8 supports the calculation for only the collinear cluster
calculation. If you want to calculate the optical conductivity
of molecular systems, you can calculate it by the following two steps:
(1) SCF calculation
First, you would perform a collinear cluster calculation using an input file Methane_OC.dat in the directory 'work' as an example. Then, you have to set the following two keywords 'Dos.fileout' and 'OpticalConductivity.fileout' as follows:
Dos.fileout on # on|off, default=off OpticalConductivity.fileout on # on|off, default=offWhen the execution is completed normally, then you can find files, System.Name.optical and System.Name.Dos.val, in the directory 'work'.
% make OpticalConductivityMainWhen the compile is completed normally, then you can find a executable file 'OpticalConductivityMain' in the directory 'work'. The optical conductivity can be calculated from the files 'System.Name.optical' and 'System.Name.Dos.val' using the program 'OpticalConductivityMain' as follows:
% ./OpticalConductivityMain met.optical met.Dos.val met.optoutwhere a methane molecule is considered as an example. Then, you are interactively asked from the program as follow:
# freqmax=100.000000 # gaussian=0.036749 freqmax (Hartree)=? 3 freq mech=? 1000In the output file 'met.optout' the second, third, and fourth columns correspond to the frequency (Hartree) and optical conductivity (arbitrary unit) for up- and down-spins, respectively.