elasic code (http://wolf.ifj.edu.pl/~jochym/Elastic.pdf, https://wolf.ifj.edu.pl/elastic/cli-usage.html#usage) was installed on clusters by Ata.

 Instruction from Ata::

For elastic I already prepared the python wheels for that. To install in your project directory please run the following commands:



module load python

cd /project/def-szpunarb

virtualenv elastic

source elastic/bin/activate

pip install elastic



Once you install it you can use it in your job script or on your command but you must first activate it using the following command



source /project/def-szpunarb/elastic/bin/activate

Run help to test:

elastic --help

Usage: elastic [OPTIONS] COMMAND [ARGS]...

Command-line interface to the elastic library.

Options:

  --vasp         Use VASP formats (default)

  --cij          Generate deformations for Cij (default)

  --eos          Generate deformations for Equation of State

  -v, --verbose  Increase verbosity

....

elastic --version

elastic, version 5.2.5.3.0+computecanada



To do calculations using command lines as described in pdf:

1) Create dir with undefornmed structure POSCAR, INCAR, POTCAR, KPOINTS files

2) Run elastic on the structure to generate deformed structures probing the properties of the system:

source /project/def-szpunarb/elastic/bin/activate

elastic -v --cij gen -n 5 -s 2 POSCAR

which generates 5 deformations of 2.0(%/degs.) per axis and writes deformation files

3) Run DFT VASP calculations on all systems in created subdirectories using the following batch script:

vi  jobdftnod 

#SBATCH --job-name=VASP_elastic_UC2

#SBATCH --account=def-szpunarb

#SBATCH --nodes=1

#SBATCH --tasks-per-node=64

#SBATCH --mem=0

#SBATCH --time=8:00:00



# Load the modules:

module purge
module load  StdEnv/2023

RSNT_LOCAL_MODULEPATHS=/project/def-szpunarb/shared/easybuild/modules module load StdEnv/2023  intel/2023.2.1  intelmpi/2021.9.0 vasp/6.5.1

P='/home/szpunarb/scratch/VASPUC2fcc/elasioUC2fccnod'

#nod -  number of deformations, including undisturbed structure (0)

nod=9

    for i in `seq 0 $nod `;

do

    cd $P

    mkdir calc-cij_00"$i"

    cd calc-cij_00"$i"

        ln -s ../INCAR ../KPOINTS ../POTCAR .

        cp ../cij_00"$i".POSCAR POSCAR

        srun vasp_std

done

nod=10

    for i in `seq 10 $nod `;

do

    cd $P

    mkdir calc-cij_0"$i"

    cd calc-cij_0"$i"

        ln -s ../INCAR ../KPOINTS ../POTCAR .

        cp ../cij_0"$i".POSCAR POSCAR

        srun vasp_std

done



4) Run elastic again to post-process the calculations. We do that by feeding it with output from the DFT calculations with undisturbed structure at the first position:

source /project/def-szpunarb/elastic/bin/activate

elastic -v --cij proc calc-cij_000/vasprun.xml calc-cij_*/vasprun.xml



The output show elastic constants athe bottom:

Reading: calc-cij_010/vasprun.xml

Cij solution

------------------------------

 Solution rank:  3

 Square of residuals: 0.00013

 Relative singular values:

 1.0000   0.7071   0.6354



Elastic tensor (GPa):

   C_11     C_12     C_44

------------------------------

 267.48   164.28   145.77

Furthermore please see some examples how to evaluate B, G, Y using Voigt/Reuss approaches: 
https://www.sciencedirect.com/science/article/abs/pii/S0022311512005259?via%3Dihub
https://sepwww.stanford.edu/data/media/public/docs/sep120/jim2/paper_html/node4.html