An entry pw_job band_structure computes the band structure. You should set screening_type to previous, and provide a converged CD file for the starting density. THERE WILL BE NO SELFCONSISTENT ITERATION, i.e. the bandstructure is plotted corresponding to the CD file, or to the atomic valence charge if no intact CD file is found. Furthermore, YOU HAVE TO USE THE FERMILEVEL OF A PREVIOUS SCF RUN. You do so by giving a line like:
fermi_level fermi_energy_in_Ryd
Default: fermi_level 0
If you want to use a different number of bands from that used in an earlier SCF loop, you may specify this number using:
number_alt_bands <number of bands for the bandstructure>
You also have to determine the lines in the BZ along which you wish to plot the bandstructure. This is done by specifying a sequence of lines in the following way:
begin bandstructure label left_middle_right kpoint startx starty startz endx endy endz number_of_bins label left_middle_right kpoint startx starty startz endx endy endz number_of_bins .. label left_middle_right kpoint startx starty startz endx endy endz number_of_bins end bandstructure
NOTE: The syntax of this structure has changed in version 5.0. Previously this ended with just end, and this has changed, so that now you need to end with end bandstructure.
All coordinates are given with respect to the reciprocal lattice vectors. The labels are mandatory; they have to be triples, separated by an underscore. Notice that xmgr allows greek characters using escape sequences (see example below).
The kpoints will be generated into the file KPOINTS. The output of the calculation can be found in the file BANDSTRUC. Energies are in eV, and are plotted against an x-coordinate that corresponds to the physical distances in cartesian k-space, i.e. 1/a.u. The file can be displayed with the popular graphics program ``xmgr''.
Example:
begin bandstructure label \8G\4_\8\D\4_X kpoint 0.0 0.0 0.0 0.0 0.0 0.5 10 label _V_W kpoint 0.0 0.0 0.5 0.0 0.5 0.5 10 end bandstructure