1. Tutorial of Practice #3 - DOS, band structure, wave function -
QnMSG
Yong-Hyun Kim

2. Density Of States (DOS)
1. Run self-consistent calculation and then run non-self-consistent calculation.
When run non-self-consistent calculation, change several parameter as follows:
- calculation=“nscf” in CONTROL namelist
- nbnd=8 (4 valence + 4 conduction) in SYSTEM namelist
- Increase the k-points
2. The program dos.x is to calculate the DOS. Structure of input data is as follows:
- The detail things about input parameter are in ref.
- dos.in -
3. Run dos.x
- /opt/espresso-5.0.1/bin/dos.x < dos.in > dos.out
4. After run dos.x, the file dos.dat is generated.
5. Visualize the DOS by gnuplot.
ref)

3. Density Of States (DOS)
1. Graphene
2. Silicon

4. Band structure Cell parameter the number of grid high symmetry points
1. Run self-consistent calculation and then for band calculation, we have to specify the k-points path. The program kpath.pl is to specify the k-points path. Input file of kpath.pl is as follows:
Cell parameter
high symmetry points
the number of grid
3. Run kpath.pl
- kpath.pl (input file)
4. After run kpath.pl, the file kpoint.dat is generated.
5. Copy the content in kpoint.dat and then paste in the K_POINTS namelist.
6. Before run non-self-consistent band calculation, change several parameter as follows:
- calculation=“bands” in CONTROL namelist
- verbosity = ‘high’ in CONTROL namelist
- nbnd=8 (4 valence + 4 conduction) in SYSTEM namelist

5. Band structure 7. Run non-self-consistent band calculation.
- /opt/espresso-5.0.1/bin/pw.x < input file > output file
8. The program bands.pl is to calculate the band structure. Run the bands.pl
- bands.pl (output file)
9. After run the bands.pl, bands.dat is generated.
10. Visualize band structure to use bands.dat by gnuplot.
- Graphene -
- Silicon -

6. Wave function 1. Run self-consistent calculation.
2. The program pp.x is to calculate wave function and charge density.
Structure of input data is as follows:
- The detail things about input parameter is in ref.
prefix: prefix of files saved by program pw.x
outdir: temporary directory where pw.x files resides
filplot: file “fileplot” contains the quantity selected by plot_num
plot_num: selects what to save in filplot
kpoint: k-point to be plotted
kband: band to be plotted
nfile: the number of data files
iflag: the types of plot
output_format: plot format
fileout: name of the file to which the plot is written
3. Run pp.x
- /opt/espresso-5.0.1/bin/pp.x < input file > output file
4. After run pp.x, the file which is xsf format is generated.
5. Visualize wavefuction by VESTA.
ref)

7. Wave function 1. Graphene 2. Silicon
k= (0.0625, , -0.1), E= eV
k= (0.625, 0.125, 0.125), E= eV
k= (0.3125, , -0.1), E= eV
k= (-0.875, 0.125, 0.125), E= eV

8. VESTA 1. To see the wavefuction, the program VESTA has to be used.
2. Run the VESTA and open the file. The detail things are in ref.
ref)