Cd Si: Difference between revisions

Latest revision as of 08:31, 14 November 2019

Overview > fcc Si > fcc Si DOS > fcc Si bandstructure > cd Si > cd Si volume relaxation > cd Si relaxation > beta-tin Si > fcc Ni > graphite TS binding energy > graphite MBD binding energy > graphite interlayer distance > List of tutorials

Task

Volume relaxtion and the calculation of the DOS and bandstructure within cubic diamond (cd) Si.

Input

POSCAR

cubic diamond
   5.5
 0.0    0.5     0.5
 0.5    0.0     0.5
 0.5    0.5     0.0
  2
Direct
 -0.125 -0.125 -0.125
  0.125  0.125  0.125

Cubic diamond Si starting lattice constant of 5.5 $\AA$ .
Fcc cell.
2 atoms in cell.

INCAR

System = diamond Si
ISTART = 0 ; ICHARG=2
ENCUT  =    240
ISMEAR = 0; SIGMA = 0.1

KPOINTS

k-points
 0
Monkhorst Pack
 11 11 11
 0  0  0

Calculation

The calculation of the optimized volume. DOS and bandstructure is similar as in the examples fcc_Si, fcc_Si_DOS and fcc_Si_bandstructure, respectively.

Volume relaxation

The bash-script loop.sh runs Si in the cubic diamond (cd) structure at several different lattice constants (5.1-5.7 Å) and collects free energy versus lattice constant into the file SUMMARY.dia:

#! /bin/bash
BIN=/path/to/your/vasp/executable
rm WAVECAR SUMMARY.dia
for i in  5.1 5.2 5.3 5.4 5.5 5.6 5.7 ; do
cat >POSCAR <<!
cubic diamond
   $i 
 0.0    0.5     0.5
 0.5    0.0     0.5
 0.5    0.5     0.0
  2
Direct
 -0.125 -0.125 -0.125
  0.125  0.125  0.125
!
echo "a= $i" ; mpirun -n 2 $BIN
E=`awk '/F=/ {print $0}' OSZICAR` ; echo $i $E  >>SUMMARY.dia
done
cat SUMMARY.dia

Example output of SUMMARY.dia:

5.2 1 F= -.10528151E+02 E0= -.10528137E+02 d E =-.274709E-04
5.3 1 F= -.10713281E+02 E0= -.10713280E+02 d E =-.218410E-05
5.4 1 F= -.10806685E+02 E0= -.10806685E+02 d E =-.114401E-06
5.5 1 F= -.10823039E+02 E0= -.10823039E+02 d E =-.429842E-08
5.6 1 F= -.10775102E+02 E0= -.10775102E+02 d E =-.204668E-09
5.7 1 F= -.10673578E+02 E0= -.10673578E+02 d E =-.112715E-10
5.8 1 F= -.10528393E+02 E0= -.10528393E+02 d E =-.552513E-11

To make a quick plot of SUMMARY.dia try:

gnuplot
gnuplot> plot "SUMMARY.dia" using ($1):($4) w lp

Extracted lattice parameter should be at 5.465 $\AA$ .

DOS

Enter (approximate) volume of 5.5 $\AA$ into the POSCAR file.

Change the INCAR according to DOS calculation (or use INCAR.dos):

System = diamond Si
ISTART = 0 ; ICHARG=2
ENCUT  =    240
ISMEAR = -5
LORBIT = 11

Use p4vasp or run the script dos.sh to calculate the DOS.

The example DOS should look like this:

Bandstructure

Enter (approximate) volume of 5.5 $\AA$ into the POSCAR file.

Change the INCAR according to bandstructure calculation (or use INCAR.band):

System = diamond Si
ISTART = 0 ; ICHARG=11
ENCUT  =    240
ISMEAR = 0; SIGMA = 0.1;
LORBIT = 11

Use p4vasp or run the script band.sh to calculate the bandstructure.

The example bandstructure should look like this:

For "fat" bands (or orbital character of bands) use p4vasp:

Mind: You will have to set the correct path to your VASP executable (i.e., BIN), and invoke VASP with the correct command (e.g., in the above: mpirun -np 2).

Download

diamondSi.tgz

Overview > fcc Si > fcc Si DOS > fcc Si bandstructure > cd Si > cd Si volume relaxation > cd Si relaxation > beta-tin Si > fcc Ni > graphite TS binding energy > graphite MBD binding energy > graphite interlayer distance > List of tutorials

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@@ Line 1: / Line 1: @@
-Description: the bash-script <tt>loop.sh</tt> runs Si in the cubic diamond (cd) structure at several different lattice constants (5.1-5.7 Å) and collects free energy versus lattice constant into the file SUMMARY.dia
+{{Template:Bulk_systems - Tutorial}}
-----
+== Task ==
-*{{TAG|INCAR}}
+Volume relaxtion and the calculation of the DOS and bandstructure within cubic diamond (cd) Si.
+== Input ==
+=== {{TAG|POSCAR}} ===
+ cubic diamond
+.5
+.0    0.5     0.5
+.5    0.0     0.5
+.5    0.5     0.0
+ Direct
+  -0.125 -0.125 -0.125
+.125  0.125  0.125
+*Cubic diamond Si starting lattice constant of 5.5 <math>\AA</math>.
+*Fcc cell.
+*2 atoms in cell.
+=== {{TAG|INCAR}} ===
   {{TAGBL|System}} = diamond Si
   {{TAGBL|ISTART}} = 0 ; {{TAGBL|ICHARG}}=2
@@ Line 8: / Line 29: @@
   {{TAGBL|ISMEAR}} = 0; {{TAGBL|SIGMA}} = 0.1
-*{{TAG|KPOINTS}}
+=== {{TAG|KPOINTS}} ===
   k-points
@@ Line 15: / Line 36: @@
   0  0
-*{{TAG|POSCAR}}
+== Calculation ==
- cubic diamond
-.5
+The calculation of the optimized volume. DOS and bandstructure is similar as in the examples {{TAG|fcc_Si}}, {{TAG|fcc_Si_DOS}} and {{TAG|fcc_Si_bandstructure}}, respectively.
-.0    0.5     0.5
-.5    0.0     0.5
+=== Volume relaxation ===
-.5    0.5     0.0
+*The bash-script <tt>loop.sh</tt> runs Si in the cubic diamond (cd) structure at several different lattice constants (5.1-5.7 Å) and collects free energy versus lattice constant into the file SUMMARY.dia:
- Direct
-  -0.125 -0.125 -0.125
-.125  0.125  0.125
-*And a simple bash-script to loop over several lattice constants: loop.sh
 <pre>
 #! /bin/bash
@@ Line 49: / Line 66: @@
 </pre>
-'''Mind''': You will have to set the correct path to your VASP executable (i.e., <tt>BIN</tt>), and invoke VASP with the correct command (e.g., in the above: <tt>mpirun -np 2</tt>).
+*Example output of SUMMARY.dia:
+.2 1 F= -.10528151E+02 E0= -.10528137E+02 d E =-.274709E-04
+.3 1 F= -.10713281E+02 E0= -.10713280E+02 d E =-.218410E-05
+.4 1 F= -.10806685E+02 E0= -.10806685E+02 d E =-.114401E-06
+.5 1 F= -.10823039E+02 E0= -.10823039E+02 d E =-.429842E-08
+.6 1 F= -.10775102E+02 E0= -.10775102E+02 d E =-.204668E-09
+.7 1 F= -.10673578E+02 E0= -.10673578E+02 d E =-.112715E-10
+.8 1 F= -.10528393E+02 E0= -.10528393E+02 d E =-.552513E-11
 *To make a quick plot of SUMMARY.dia try:
@@ Line 56: / Line 80: @@
   gnuplot> plot "SUMMARY.dia" using ($1):($4) w lp
-== Used INCAR Tags ==
+*Extracted lattice parameter should be at 5.465 <math>\AA</math>.
-{{TAG|ENCUT}}, {{TAG|ICHARG}}, {{TAG|ISMEAR}}, {{TAG|ISTART}}, {{TAG|SYSTEM}}
+=== DOS ===
+*Enter (approximate) volume of 5.5 <math> \AA </math> into the {{TAG|POSCAR}} file.
+*Change the {{TAG|INCAR}} according to DOS calculation (or use INCAR.dos):
+ System = diamond Si
+ ISTART = 0 ; ICHARG=2
+ ENCUT  =    240
+ ISMEAR = -5
+ LORBIT = 11
+*Use p4vasp or run the script ''dos.sh'' to calculate the DOS.
+*The example DOS should look like this:
+[[File:Fig cdSi 1.png|300px]]
+=== Bandstructure ===
+*Enter (approximate) volume of 5.5 <math> \AA </math> into the {{TAG|POSCAR}} file.
+*Change the {{TAG|INCAR}} according to bandstructure calculation (or use INCAR.band):
+ System = diamond Si
+ ISTART = 0 ; ICHARG=11
+ ENCUT  =    240
+ ISMEAR = 0; SIGMA = 0.1;
+ LORBIT = 11
+*Use p4vasp or run the script ''band.sh'' to calculate the bandstructure.
+*The example bandstructure should look like this:
+[[File:Fig cdSi 2.png|300px]]
+*For "fat" bands (or orbital character of bands) use p4vasp:
+[[File:Fig cdSi3.png|800px]]
+'''Mind''': You will have to set the correct path to your VASP executable (i.e., <tt>BIN</tt>), and invoke VASP with the correct command (e.g., in the above: <tt>mpirun -np 2</tt>).
 == Download ==
-[http://www.vasp.at/vasp-workshop/examples/diamondSi.tgz diamondSi.tgz]
+[[Media:DiamondSi.tgz| diamondSi.tgz]]
-----
-[[VASP_example_calculations|To the list of examples]] or to the [[The_VASP_Manual|main page]]
+{{Template:Bulk_systems}}
+Back to the [[The_VASP_Manual|main page]].
 [[Category:Examples]]