VASP Example: Calculate Energy-Lattice Parameter curve for MnBiNi
The necessary tools to perform the basic calculations to investigate the lattice parameter for MnBiNi and the cohesive energy determination have been shown in this page. We need at least 4 input files and one file has the secript for your calculation
Note: The page is under a continuous developing stage.
Contents |
POSCAR
The file (position card) defines the box size corresponding to the near equilibrium fcc lattice structure of one al atom:
MnBiNi 5.28 0.500 -0.866 0.000 0.500 0.866 0.000 0.000 0.000 1.45 2 2 2 direct 0.0000 0.0000 0.0000 Mn 1 0.0000 0.0000 0.5000 Mn 2 0.3333 0.6667 0.2500 Bi 3 0.6667 0.3333 0.7500 Bi 4 0.3333 0.6667 0.7500 Ni 5 0.6667 0.3333 0.2500 Ni 6
POTCAR
The Potential Card can be downloadable from: /usr/local/vasp/ Depending on which potential you would like to use, go to:
- PAW (Projected augmented wave),
- PAW-GGA (Projected augmented wave-generalized gradient approximation),
- PS (Pseudopotential) etc.
To access these files you need to be a member of vasp group. There are four sub-folders: pot, pot_GGA, potpaw, and potpaw_GGA at /usr/local/vasp/.
KPOINTS
The number of nodal points to calculate the solution; in mesh refinement the greater the number the better the answer but is more costly
4x4x4 Comment 0 0 = automatic generation of k-points Monkhorst M use Monkhorst Pack 4 4 4 grid 4x4x4 0 0 0 shift (usually 0 0 0)
INCAR
Input Card to solve the Schrodinger Equation
LWAVE = .FALSE. LCHARG = .FALSE. LREAL = .FALSE. ADDGRID = .TRUE. PREC = Accurate EDIFF = 1e-05 ENCUT = 400.0000 ALGO = Fast #NBANDS = 168 IBRION = 1 LMAXMIX = 4 LDAU= .TRUE. LDAUTYPE = 2 LDAUL = 2 -1 2 LDAUU = 6.0 0.0 5.0 LDAUJ = 1.0 0.0 1.0 ISPIN=2 VOSKOWN=1 LORBIT=11 MAGMOM = 2*4 2*0 2*2 ISIF =3
Script
rm WAVECAR for i in 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 6.0 do cat >POSCAR <<! MnBiNi $a 0.500 -0.866 0.000 0.500 0.866 0.000 0.000 0.000 1.45 2 2 2 direct 0.0000 0.0000 0.0000 Mn 1 0.0000 0.0000 0.5000 Mn 2 0.3333 0.6667 0.2500 Bi 3 0.6667 0.3333 0.7500 Bi 4 0.3333 0.6667 0.7500 Ni 5 0.6667 0.3333 0.2500 Ni 6 ! echo "a=$i" ; vasp_5212_talon E=`tail -1 OSZICAR` ;echo $i $E >> SUMMARY.fcc done cat SUMMARY.dat
Result
we got diffrent output files and for our gole here we make file named SUMMARY.dat from the scrip. Summery file should have two comunt one for diffrent lattice parmeter and the other for the energy . We plot this data. </pre>
Where the lattice parameter A0 = 4.52 Angstrom. Cohesive energy Emin = -2.659 eV.
for more sources of input files you can looking for matrial project *[1]
