3.9 what='plot_bz'

With this option the code writes a script to make a plot of the Brillouin zone (BZ) and of the path (the default one or the one given in input). The script must be read by the asymptote code, available at http://asymptote.sourceforge. net/. In many Linux distributions this code is available as a separate package, but it is not installed by default.
The following variables control the plot:

lasymptote  : if .TRUE. asymptote is called by the program and 
              the pdf file with the plot of the BZ is produced.
              Default: logical .FALSE.
flasy       : initial part of the name of the file where the 
              asymptote script is written and of the name of the 
              pdf file.
              Default: character(len=*) 'asy_tmp'
asymptote_command  : the command that invokes asymptote and 
              produces the pdf file of the BZ.
              Default: character(len=*) 'asy -f pdf -noprc 
              flasy.asy'
npx         : used only in the monoclinic cell, this parameter 
              is needed to determine the shape of the Brillouin 
              zone. The default value is usually large enough, 
              but for particular shapes of the monoclinic 
              Brillouin zone it could be small. If the code 
              stops with an error asking to increase npx, double 
              it until the error disappears.
              Default: integer 8

The structure of the solid can be seen using the XCrySDen code reading the input file of pw.x. You can find the code at http://www.xcrysden.org/. THERMO_PW produces also a file in the xsf format called prefix.xsf, where the variable prefix is given in the input of pw.x. This can be useful when the nonequivalent atomic positions and the space group are given in the input of pw.x. To see an xsf file, give the command xcrysden -xsf file.xsf.

With this option the code produces also a file with the X-ray powder diffraction intensities for the solid. A plot shows the scattering angles and the relative intensity of each peak. Note that this plot is made using a superposition of atomic charges, not the self-consistent charge. By setting the flag lformf=.TRUE. the atomic form factors of all the atomic types used to calculate the intensities are plotted. By setting the flag lxrdp=.TRUE. the intensities plot is done also after the cell optimization and after a self-consistent calculation for the options that support it. The variables that control these plots are:

lambda      : The X-ray wavelength (in A) used to calculate the 
              scattering angles.
              Default: Cu alpha line 1.541838 A if lambda_element 
              is empty
lambda_elem : The anode element, used to set the X-ray 
              wavelength. Supported elements 'Cr', 'Fe', 'Co', 
              'Cu', 'Mo'. NB: lambda must be zero to use 
              lambda_elem, otherwise the value of lambda given 
              in input is used.
              Default: character(len=2) ' ' 
flxrdp      : name of the file where the scattering angles and 
              intensities are written.
              Default: character 'output_xrdp.dat'
flpsxrdp    : name of the postscript file with the X-ray 
              diffraction spectrum.
              Default: character 'output_xrdp'
lxrdp       : if .TRUE. compute the xrdp also after the cell 
              optimization with all the options mur_lc_... 
              with the uniformly strained atomic positions 
              and after the scf calculation if supported by 
              the option. 
              Default: logical .FALSE.
lformf      : if .TRUE. plot also the form factor of each 
              atom type present in the solid. Note that the 
              atom type is recognized from the atom name in 
              the thermo_pw input. The name must coincide 
              with the symbols in the periodic table. (Cu, H, 
              Li, Li1, ... are correct, CU, LI, H1 ...  are 
              wrong).
              Default: logical .FALSE.
smin        : minimum value of s used in the atomic form 
              factor plot.
              Default: real 0.0
smax        : maximum value of s used in the atomic form 
              factor plot.
              Default: real 1.0
nspoint     : number of points in which the atomic form 
              factor is calculated.
              Default: integer 200
lcm         : when .TRUE. the code uses the Cromer-Mann 
              coefficients form the International Tables of 
              Crystallography to compute the atomic form 
              factors, otherwise uses the Doyle-Turner or 
              Smith-Burge parameters.
              Default: logical .FALSE.
flformf     : name of the file in which the atomic form 
              factor is written. The code adds a number to 
              each file name and creates a file per atom type.
              Default: character 'output_formf.dat'
flpsformf   : name of the postscript file with the atomic 
              form factor. The code adds a number to each 
              file name and creates a file per atom type.
              Default: character 'output_formf'