Practice 3 Electronic structure YongHyun Kim NST 551
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Practice #3: Electronic structure Yong-Hyun Kim NST 551
Scf calculation 1. To plot DOS, band structure, charge density, you have to run scf calculation first. 2. Modify the INCAR from the INCAR used in practice #2. LORBIT = 11 LWAVE=. TRUE. LCHARG=. TRUE. 3. Run scf calculation.
Density of State (DOS) 1. For DOS calculation, the CHGCAR from previous scf calculation is needed. 2. Copy previous CONTCAR to POSCAR. 3. Modify the INCAR from the INCAR used in scf calculation. ICHARG = 11 NEDOS = 4000 LORBIT = 11 ISMEAR = -5 NSW = 0 IBRION = -1 LCHARG=. FALSE. 1. Increase the number of sampling k-point Ex) 6 6 1 => 12 12 1 (2 times) 2. Run non-scf calculation. 3. Extract a file ‘DOS 0’ to plot total DOS. > vasp-ldos. sh DOSCAR –np 0
Density of State (DOS) 7. Plot ‘DOS 0’ using gnuplot. <graphene> <Si>
Band structure 1. For band calculation, the CHGCAR from previous scf calculation is needed. 2. Copy CONTCAR to POSCAR 3. Modify the INCAR from the INCAR used in scf calculation. ICHARG = 11 NSW = 0 IBRION = -1 4. Modify the KPOINTS from the KPOINTS used in scf calculation. Graphene 10 Line-mode rec 0. 0 0. 5 0. 0 ! gamma !M 0. 5 0. 0 0. 33333 0. 666667 0. 0 !M !K 0. 33333 0. 666667 0. 0 !K ! gamma The number of grid per each passes. High symmetry points (sampling passes).
Band structure 5. Run non-scf calculation. 6. Extract a file ‘band. dat’ to plot band structure > bandplot. x 7. Plot 'band. dat' using gnuplot. <graphene> <Si>
Charge density 1. For charge density calculation, the WAVECAR from previous scf calculation is needed. 2. Copy CONTCAR to POSCAR 3. Modify the INCAR from the INCAR used in scf calculation. ISTART=1 LPARD=. TURE. IBAND=1 KPUSE=5 LSEPB=. TURE. LSEPK=. TURE. 4. Run non-scf calculation. N-th band you want to plot. N-th k-point you want to plot. N-th band 5. Download charge density file 'PARCHG. 0001. 0005' to window. > sz PARCHG. 0001. 0005 N-th k-point
Charge density 6. Plot 'PARCHG. 000#' using a program VESTA in window. You can download VESTA from following link http: //jp-minerals. org/vesta/en/download. html 7. Check the energy and k-point coordination which you set from the PROCAR. <graphene> <Si>
VESTA 1. To see the charge density, you need to use the program VESTA. 2. Rename the file 'PARCHG. 000#' you downloaded with special form like 'xxxxxx CHGCAR' 3. Run the VESTA, and open the file 'xxxxxx CHGCAR' http: //jp-minerals. org/vesta/en/download. html
Appendix: Gnuplot commands • Naming axis > set xlab "label" > set ylab "label" > set zlab "label" • Set axis ranges > set xrange[min: max] > set yrange[min: max] > set zrange[min: max] • Canceling all setting > set autoscale // for all axis > set autoscale 'x' // for x-axis • Plotting several functions > pl 'filename' u 1: 2 w l t 'text 1', 'filename' u 1: 3 w l t 'text 2' • Shifting axis > pl 'filename' u ($1+100): 2 w l > pl 'filename' u 1: ($2*100) w l // x-axis +100 // y-axis * 100 http: //www. gnuplot. info/ http: //wiki. kldp. org/Korean. Doc/html/Gnu. Plot-KLDP/
