Properties ; Plot DOS, Band Structure, Charge/Spin Density Contour, Optical Properties, MCD, and Frozen Phonons.

Click Properties. $\Rightarrow$Properties Window will appear. There are six properties to plot; Density of States, Band Structure, Charge/Spin Density, Optics (for Bulk mode only), MCD, and Frozen Phonons. Click one of the boxes to choose.

2.5.1

Density of States ; Click Density of States. There appears the Density of States window with three parts, which are Set up, Run FLAPW, and Generate; View/Print.

• Click Set up. $\rightarrow$k-points Settings Window will appear.
  Change inputs from your SCF calculations if desired (See 2.3.2 (M)). Click Done.

• Click Run FLAPW. The runtime and status will be shown below the box.

• Click View/Print when the status of Run FLAPW says 'Done'. $\rightarrow$DOS Plotting Window will appear.
  1. Data files available for DOS plotting are shown in the blue left top window. Double click to choose. Files chosen will appear in the right window. User may remove files from the right window by a double click.

  2. Click Show full range to view DOS plot. Click Clear to clear it.

  3. Enter 'Title', 'Ymax', 'Emin', and 'Emax' and press $\langle$Enter$\rangle$ key to make changes in the DOS plot. Make sure that the changes are reflected in the plot. (Refer to the instruction on the right of the DOS plot.)

  4. Enter PS file name (without.ps suffix) and click Generate PostScript figure. The postscript file is generated in the working directory and listed in the file name to choose and click View. Click Delete to delete the file chosen.

  5. Click Done to finish.

• Click Done to finish.

2.5.2

Band Structure; Click Band Structure. There appears the Band Structure window with three parts, which are Set up, Run FLAPW, and View/Print.

• Click Set up. $\rightarrow$Band Structure Window will appear.
  1. Enter the k-points defining the high symmetry lines along which the band structures will be plotted. User may choose from the default values appearing in the 'Default Line Sets' window on the bottom, by clicking one of the sets. The choice will be shown in the large blue window at the top.

  2. Add, Edit or Delete k-points; click one of the line sets on the blue window to choose, make changes in the small boxes below that window and click Add, Edit, or Delete.

  3. Enter the energy range to be plotted, that is, the minimum (negative) and maximum (positive) energy around the Fermi energy (located at zero) in eV.

  4. Enter the Page Annotation if desired.

  5. Click Save and Quit or Cancel.

• Click Run FLAPW. The runtime and status will be shown below the box.

• Click View/Print (when the Run FLAPW says 'Done') to see the ghostscript file (band.s1s2.ps) and print it out.

• Click Done to finish.

2.5.3

Charge/Spin Density; Click Charge/Spin Density. There appears the Charge/Spin density window with three parts, which are Set up, Run FLAPW, and Generate; View/Print.

• Click Set up. $\rightarrow$Charge/Spin Density Window will appear.
  Follow the instruction shown in the upper right box to enter the inputs defining the plane for charge/spin density contour plot. Click Add to add your input. If you have more than one plane, repeat it. Click the number on the blue window to choose, make changes and click Edit or Delete if desired.

• Click Run FLAPW. The runtime and status will be shown below the box.

• Click Generate; View/Print when the status of Run FLAPW says 'Done'. $\rightarrow$Charge/Spin Density Plot Window will appear.
  1. Data files available for plotting are shown in the blue left top window. There will be one data file for non-magnetic systems, that is, Total charge density. There will be four data files for magnetic systems; which are, Total, Spin-Up, Spin-Down, and Up-Down (i.e. Spin charge) charge densities. click to choose - as many as you want to plot in one page. Files chosen will appear in the right window. User may remove from the right window by a double click.

  2. Enter 'PS file name' and 'Figure annotation' (which will appear at the bottom of the page). Click each of the plots shown in the upper right window and enter the 'Box annotation' for each.

  3. Choose contour type (either 'Color' or 'Black&White') and the background color (either 'White' or 'Black') by clicking on the corresponding boxes.

  4. Click Generate PostScript File. $\rightarrow$ The files generated will be listed in the 'View Charge/Spin Density Plot' Window at the bottom.

  5. Click on a file in the bottom window to choose. Click View to see the result or 'Delete' to delete the postscript file.

  6. Click Done to finish.

• Click Done to finish.

2.5.4

Optics; Click Optics. There appears the Optics window with five steps of input. Click each button one by one to enter the requird input.

• Step 1. Generate list of k-points; There appears k-point generation for dielectric function calculation window.
  1. Enter # of k-points in the irreducible Brillouin Zone for dielectric function calculation. Upon running FLAPW, the tetrahedral k-points will be automatically generated and saved in a 'spkpt.init' file in the working directory. Click Full BZ? box to use the k-points in the full Brillouin Zone.

  2. Chose either On or Off for the k-mesh refinement feature. This will allow one to refine the k-meshes around a certain k-point within a given radius. Upon choosing On, enter (i) the Cartesian coordinates of the center k-point, kx, ky, and kx, (ii) the radius of the region to be refined in a.u. and (iii) the number of k-points to be generated in the region.

     This feature will allow the user to refine the k-point meshes around a selected k-point. The region and the extent of refinement are specified by the Cartesian coordinate of a k-point, the radius of the sphere centered at this point and the number of k-points to be generated in the sphere. The code will generate a dense mesh inside the sphere to meet the refinement specification and recalculate the weights of the tetrahedra according to their volume. Refined k-point meshes could be useful when the most important optical spectra close to the absorption edge are determined by the electronic states within a fairly small portion of the BZ close to a few critical points which are generally not included in the regular Monkhorst-Pack meshes. Instead of using thousands of k-points inside the IBZ to resolve this optical spectra, the code calculates the bands around the specific region with a high resolution to discover the fine structure of the absorption edge while the other parts of the IBZ are sampled with less accuracy but yielding a reasonable representation of the optical spectra.

  3. Click Generate K-points file. To view the output file, "prepout", click Inspect output file button. This file has the information about the k-points and tetrahedra.

  4. Click Quit to finish

• Step 2. Generate optical transition matrix; clicking this button, starts the FLAPW run to generate the optical transition matrix. Before clicking this button, choose from either tranverse form or longitudinal form. The longitudinal expression (i.e. exponential form) is best employed for the nonlocal methods such as sx-LDA and Model GW, while the tranverse expression (i.e. the momentum matrix) can used for the LDA. This is the most time-consuming part. Note that the longitudinal form takes roughly four times longer than the tranverse form. There appears Running time in a small window. The View output button shows the result, "lapwout" file.

• Step 3. Set parameters for dielectric function: there appears Optical Properties window.
  1. Choose how to determine the Fermi energy by clicking on Enter # of valence electrons box. You may specify either the # of valence electrons or the Fermi energy. For both, you may either type the # of valence electrons or Fermi energy by hand in the small box or read from the self-consistent FLAPW calculation by clicking the Estimate box.

  2. Enter the Temperature, Drude damping parameter ($\Gamma$ in Ev), Thickness in microns for transmissivity, and the Output Energy Units. The temperature effect will be simulated by Fermi-Dirac statistics whenever a non-zero temperature value is specified.

  3. On the upper right box, choose the features that you want to include in your calculation.
     • Edge refinement; refines the tetrahedra around the Fermi energy to get an accuarte absorption edge. In this procedure, a new k-points sampling is introduced to find the eigenvalues coinciding with the Fermi level and a new set of tetrahedra decomposition is obtained for this new refinement to find the accurate band edge. Information is saved in a file "refine.dat".                 

     • Fixed # of valence bands; specifies the # of valence electrons to be filled. In this case, a finite temperature and edge refinement are ignored. This would be useful for erroneous semimetal states by LDA.

     • Scissor-operator; introduces the scissors operator for adjusting the band gap.

     • Peak analysis; analyzes which band transitions correspond to the peaks between plow and phigh in Im[$\epsilon$].

  4. Click OK to go back to the Optics window.

• Step 4. Calculate dielectric function; Dielectric functions are calculated.

• Step 5. View and print optical properties; this generates various optical properties. On the Optical properties plots window, click to choose from Im(eps), Re(eps), N, K, R, EELS, and alspha, etc. Also choose the energy unit from eV, THz, Hartree, Kem-1, nm, and microns. If desired, make changes in the X- and Y- axes ranges. Enter the name of the postscript file in the file box and click Create Postcript file to save the plot as a postscript file.

2.5.5

MCD; Click MCD. There appears the MCD window with three parts, which are Set up, Run FLAPW, and Generate; View/Print. GUI let the user plot the cross sections of core-valence transitions.

• Click Set up. $\rightarrow$MCD Setup Window will appear.
  1. A blue window lists all atoms of your system, with the status exclude. To calculate the MCD, click on the atom from the list, and then select core state(s) from the window at the bottom left. Status of the atom exclude will change to include.

  2. Enter the number of energy meshes for the MCD plot, energy cut-off above the Fermi energy for the valence states (eV), and the type of the line shape from three choices(Gauss, Lorentz and Doniac-Sunjic), and the line parameter.

  3. Click OK to finish the setup.

• Click Run FLAPW.

• Click Generate; View/Print. Double click on one of the atoms from the top right panel to choose(Double click again to abort). You can choose one atom at a time. Choose polarization components by clicking on left circular, right circular, and z-polarized

  on the top of the plotting window. The calculated cross sections results will be shown. Enter the title, and change the maximum and minimum values of x- and y- axis, if desired. Also there are Change MCD parameters and Recalculate MCD buttons.

• Enter the PS file name and click Created postscript file to save the file. You can View or Delete the saved file.

2.5.6

Frozen Phonon; Click Frozen Phonon. There appears the Frozen Phonon window with three parts, which are Set up, Run FLAPW, and View Results.

• Click Set up. $\rightarrow$Setup Frequency Calculations Window will appear.
  1. The left top window lists all atoms of your system. To calculate the frequency, click on the atom from the list, and then enter the direction and amount (in a.u.) of the shift and click Add. Make sure your inputs appear on right top window correctly. To edit/delete, click to choose from the list of the right top window, make changes and click Edit or Delete.

  2. Click to choose/abort obeying the symmetry requirement.

  3. Click OK to finish the setup.

• Click Run FLAPW.

• Click View Results. Calculated results of the dynamical matrix, eigenmodes and eigenvectors are displayed.

(NOTE)
The 'lapwin' and 'lapwout' files for the self-consistent, and each property, calculations are saved with the extension, '.scf', '.bnd', '.chd', and '.dos', respectively, in the working directory.