In order to optimize the lattice constants and the whole crystal structure, we usually perform many DFT runs and plot the energy for each structure. I find that annoying and time consuming. The goal here is to write a script which would automatically generate multiple structure files, perform DFT calculation obtain the converged value of energy and store it to some file.

Here are the files you need before you use this script

• struct file with original lattice constants with name a0c0.struct
• a0c0.inM file for the relaxation of the internal parameter
• Of course this script optimize.sh
• If you are submitting to cluster then you need a submit script in which the path to Wien2k executible is defined.

• Check the length of a_new and c_new and find if it's equal to original a and c

  ** Because wien2k very specific about the character length in struct file.

  ** may be I should put a counter here

  ** Remember ${#var} will give you the length of the var

  ** So a simple if statement should do the job.

• I am assuming after one job finishes the flag in inm remains MSR1a check it out. ** That assumption turned out to be false. So I later put a checker for it.

• More realistic one would be to find the minimum itself instead of having an Energy.dat file ** But that would take little bit long time.