qe_convergence_test_k_points

#!/bin/bash

# run in directory containing input files for a CASTEP run

first_kpoint=$1
final_kpoint=$2
kpoint_step=$3

ry_to_ev=13.605698066

if [ ! -f k_points.txt ]; then
        echo "K-point grid; Total calculated energy per atom [eV]; Time [s]" >> k_points.txt
fi

for kpoint in `seq $first_kpoint $kpoint_step $final_kpoint`; do
	
	mkdir ${kpoint}_k_points	
	cp *upf ${kpoint}_k_points
	cp *UPF ${kpoint}_k_points
	
	sed "s/AAA/${kpoint}/gi" pw.in > ${kpoint}_k_points/pw.in
	
	cd ${kpoint}_k_points 

	mpirun -np $NCORES pw.x -i pw.in > pw.out

	energy=`awk '/total energy/ {print $5}' pw.out | tail -2 | head -1`

        time=`awk '/WALL/ {print $5}' pw.out | tail -1`

        # determine number of atoms per UC in order to calculate the total energy per atom

        natoms_raw=`awk '{IGNORECASE=1}; {FS="="}; /nat/ {print $2}' pw.in`
        natoms=`echo ${natoms_raw%,*}`
        energy_per_atom=`python3 -c "print(float('$energy')*float('$ry_to_ev')/float('$natoms'))"`

        echo "$kpoint x $kpoint x $kpoint" $energy_per_atom $time >> ../k_points.txt

	rm -r *.save

	cd ..
done