VASP and Gnuplot should be installed prior to running these scripts.
Other interesting repositories can be found on my personal website: sufyanshk.github.io
MPIRUN is used for parrallel runs of vasp_std.

These are bash and gnuplot scripts to do strucutrual relaxations and get precise lattice parameter using Vienna Ab-initio Simulaiton Package (VASP).
POSCAR and KPOINTS files are updated during runtime of the respective scripts. Kindly edit the evsvol_coarse.sh, evsvol_fine.sh and kp_optimisation.sh files before running the scripts.
The .plt files are used for plotting E vs. k-points and E vs. lattice parameter plots.

Steps:

1. Put KPOINTS, POSCAR and POTCAR files.
2. Edit the evsvol_coarse.sh file and write in it:
   • Energy cut-off
   • Crystal-system name (POSCAR system for which you want to calculate the lattice parameter)
   • No. of cores on which you want to run the VASP calculations
3. nohup evsvol_coarse.sh & so that the calculations run in the background.
4. Check the nohup.out file for the output messages. (If summary1.eps file is generated then it means your calculations are over)
5. Edit the evsvol_fine.sh similar to step-2. Reduce the step size of lattice parameter change.
6. nohup evsvol_fine.sh & so that the calculations run in the background.
7. Check the nohup.out file for the output messages. (If summary2.eps file is generated then it means your calculations are over)
8. Edit the kpoint_optmsn.sh file for desired K-point density.
9. nohup kpoint_optmsn.sh & so that the calculations run in the background.
10. Check the nohup.out file for the output messages. (If summary3.eps file is generated then it means your calculations are over)

This program is not affiliated with VASP.
You are free to modify it, but do so at your own risk.