Tutorial for Elasticity tool (1) Select (2) Depress For speed, an elastic calculation should be preceded by a careful optimization of atom coordinates in the experimental cell data. pyrite Select
Mar 26, 2015
Tutorial for Elasticity tool
(1) Select
(2) Depress
For speed, an elastic calculationshould be preceded by a careful
optimization of atom coordinatesin the experimental cell data.
pyrite
Select
VASP interface dialog
The k-mesh suggestion and info is implemented in the same way as for ABINIT
For the various options, consult the VASP manual e.g. at: http://cms.mpi.univie.ac.at/vasp/vasp/vasp.html
Select
If unsure,select the
first potential
The suggestion was 3x3x3, which would be OK for an insulator, but sulfides border on the metallic behaviour. The k-mesh was accordingly upped to 5x5x5.
INCAR is proposed for editing
Fine-tune the VASP execution flags for your exact purposes
Echoes for questions asked
optimization constraintsare implemented
This is an easy case because the material is cubic P.Centered cubics, tetragonals etc. are a lot less trivial.
The user is relieved from all this tedium.
The KPOINTS file
The RunJob.bat file for Windows
The PostProc.bat file
Toth utility context
import relaxed structure with
total energy intoJOBreport.out
import stress
Double-click
A DOS window appears.VASP is running.
Start the execution
The DOS window disappears
Execute PostProc.bat: JobReport.out grows by 1 kB
Double-click
JobReport.outgrows by 1kB
JobReport now contains the optimizedcrystallographic description for pyrite.
Let’s import it.
Select
Depress
Tutorial for Elasticity tool
(1) Select
(2) Depress
Last chance to modifyengine selection.
Type
This is the only elasticity-related info requiredfor a successful elasticity run
If unsure, justclick OK.
You will not getthe fastest nor
the most preciseresults, but acompromise.
VASP interface dialog is purely about individual optimizations
The k-mesh suggestion and info is implemented in the same way as for ABINIT
For the various options, consult the VASP manual e.g. at: http://cms.mpi.univie.ac.at/vasp/vasp/vasp.html
All the elastic-related data
is processed inthe background
Suggestion was 3x3x3. Increase a bit because pyrite
is not truly an insulator.
Depress
If in doubt,don’t alter.It may not be fast, but
it willget there.
Numerous POSCARXX input data files have been created,one for each distortion
The JOBreport.out file contains data on the distortions used
Double-click on RunJob.batch to start the job
Many output files have appeared
Double-click.JOBreportincreasesby 3 kB
Least squares analysis has been run in the background
symmetry constraints on elastic coefficients
least squares analysisof quantum results
Experimental values:Simmons & Birch (1963) C11 381.8 GPa C12 31.0 C44 109.4
The matrix laid out numerically. Hexagonal
cases may not be astrivial as this one.
Negative diagonal elementswould mean that the phase
is not stable.
equivalent isotropic coefficients
speed of sound
Debye temperature
Bulk, shear, Young’s coefficients etc.. have been extracted.
copy to clipboard with <CTRL><C>
then transfer toview property screen
Now produce radial plots of elasticity
Paste into the Property dialog
paste
type
Depress
Radial plot of thesmall shear coefficient
in pyrite
End of Elasticity tutorial