Fcc Ni

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Revision as of 12:01, 10 May 2017 by Karsai (talk | contribs)

Task

Lattice parameter optimization, calculation of the DOS and bandstructure in (spin-polarized) fcc Ni.

Input

POSCAR

fcc:
 3.53 
 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 Ni
  ISTART = 0 ; ICHARG=2
  ENCUT  =    270
  ISMEAR =    1  ; SIGMA = 0.2
  LORBIT = 11
  ISPIN = 2
  MAGMOM = 1
  • Initial charge-density from overlapping atoms in starting job.
  • Default energy cutoff of 270 eV used (ENCUT=270).
  • MP smearing used since we have a metal.
  • Spin-polarized calculation ISPIN=2, initial moments of 1 (MAMOM=1).
  • Static calculation.

KPOINTS

k-points
 0
Monkhorst Pack
 11 11 11
 0  0  0
  • Equally spaced k mesh with 56 points in the IBZ.
  • Odd, -centered mesh.

Calculation

The calculations are carried out in analogy to cd Si.

Volume relaxation

  • The bash-script loop.sh runs fcc Ni at several different lattice constants (3.0-3.9 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 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 ; 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 -n 2 $BIN
E=`awk '/F=/ {print $0}' OSZICAR` ; echo $i $E  >>SUMMARY.fcc
done
cat SUMMARY.fcc
  • With the bash-scripts dos.sh and band.sh compute the DOS and bandstructure of fcc Ni, respectively.

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

fccNi.tgz


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