Fcc Si: Difference between revisions
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== Task == | == Task == | ||
Lattice constant optimization | Lattice constant optimization for fcc Si. | ||
== Input == | == Input == | ||
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{{TAGBL|ENCUT}} = 240 | {{TAGBL|ENCUT}} = 240 | ||
{{TAGBL|ISMEAR}} = 0; {{TAGBL|SIGMA}} = 0.1 | {{TAGBL|ISMEAR}} = 0; {{TAGBL|SIGMA}} = 0.1 | ||
*Initial charge density form overlapping atoms. | |||
*Energy cutoff of 240 eV from {{TAG|POTCAR}} file. | |||
=== {{TAG|KPOINTS}} === | === {{TAG|KPOINTS}} === | ||
Revision as of 14:01, 4 May 2017
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
Lattice constant optimization for fcc Si.
Input
POSCAR
fcc Si: 3.9 0.5 0.5 0.0 0.0 0.5 0.5 0.5 0.0 0.5 1 cartesian 0 0 0
INCAR
System = fcc Si ISTART = 0 ; ICHARG = 2 ENCUT = 240 ISMEAR = 0; SIGMA = 0.1
- Initial charge density form overlapping atoms.
- Energy cutoff of 240 eV from POTCAR file.
KPOINTS
k-points 0 Monkhorst Pack 11 11 11 0 0 0
Calculation
- The bash-script loop.sh runs fcc Si at several different lattice constants (3.5-4.3 Å) and collects free energy versus lattice constant into the file SUMMARY.fcc
#! /bin/bash
BIN=/path/to/your/vasp/executable
rm WAVECAR SUMMARY.fcc
for i in 3.5 3.6 3.7 3.8 3.9 4.0 4.1 4.2 4.3 ; do
cat >POSCAR <<!
fcc:
$i
0.5 0.5 0.0
0.0 0.5 0.5
0.5 0.0 0.5
1
cartesian
0 0 0
!
echo "a= $i" ; mpirun -np 2 $BIN
E=`awk '/F=/ {print $0}' OSZICAR` ; echo $i $E >>SUMMARY.fcc
done
cat SUMMARY.fcc
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).
- To make a quick plot of SUMMARY.fcc try:
gnuplot gnuplot> plot "SUMMARY.fcc" using ($1):($4) w lp
Download
To the list of examples or to the main page