VASP: Ideal Shear Strength of Au

Input files

Here are the basic input files required for VASP calculation. Some of the files need to be changed since we need to perform a large number of calculations.

INCAR

System = fcc Au
LWAVE = .FALSE.
ENCUT  =  400
ISMEAR  = 1
SIGMA = 0.2
ISIF = 2

To increase plane wave cutoff, we manually put PREC = HIGH or PREC = Accurate. Default value is PREC = Medium

KPOINTS

43x43x43
0        0 = automatic generation of k-points
Monkhorst
43 43 43
0 0 0

POSCAR

POSCAR for FCC Au (created by tcl)
4.0615
 0.612372435696  0.000000000000 -0.353553390593
 0.408248290464  0.577350269190  0.000000000000
 0.612372435696  0.000000000000  0.353553390593
1
Cartesian  (real coordinates r)
0    0    0

You also need to put the LDA pseudopotential file as POTCAR in this directory.

Results

Perfect crystal

First, we perform a test simulation in which we relax the electrons in a gold perfect crystal.

 qsub vasp.pbs

The vasp.pbs script is listed below.

#!/bin/bash
#PBS -N Au_perf.43.E4.8
#PBS -j oe
#PBS -l nodes=1:ppn=8,walltime=24:00:00
#PBS -V

### ---------------------------------------
### BEGINNING OF EXECUTION
### ---------------------------------------

echo The master node of this job is `hostname`
echo The working directory is `echo $PBS_O_WORKDIR`
echo This job runs on the following nodes:
echo `cat $PBS_NODEFILE`

ncpu=`cat $PBS_NODEFILE | wc -w`
echo "Number of processors = $ncpu "

### end of information preamble

cd $PBS_O_WORKDIR
echo $PWD
/opt/mpiexec/bin/mpiexec --comm=pmi -np $ncpu ../../../../bin/vasp.caiwei.mva2 >& $PBS_O_WORKDIR/vasp.log

We run this test case on SU-AHPCRC. The calculation takes 160 seconds (on 8 CPUs) to finish. The ground state energy is E = -4.3951 eV.

Shear deformation

 qsub tcl.pbs