tutorial for elasticity tool (1) select (2) depress for speed, an elastic calculation should be...

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