#!/bin/sh

# run from directory where this script is
cd `echo $0 | sed 's/\(.*\)\/.*/\1/'` # extract pathname
EXAMPLE_DIR=`pwd`

# check whether echo has the -e option
if test "`echo -e`" = "-e" ; then ECHO=echo ; else ECHO="echo -e" ; fi

$ECHO
$ECHO "$EXAMPLE_DIR : starting"
$ECHO
$ECHO "This example shows how to calculate interatomic force constants in"
$ECHO "real space for Fe."

# set the needed environment variables
#. ../../../environment_variables

BIN_DIR=$TOPDIR/home/krishna/QE/qe-6.2/bin
#BIN_DIR=$TOPDIR/bin
PSEUDO_DIR=$TOPDIR/home/krishna/QE/qe-6.2/pseudo
#PSEUDO_DIR=/pseudo
#PSEUDO_DIR=$TOPDIR/pseudo
#PSEUDO_DIR=$TOPDIR/qe-6.2/pseudo
TMP_DIR=$TOPDIR/home/krishna/QE/qe-6.2/tmpdir


# required executables and pseudopotentials
BIN_LIST="pw.x ph.x q2r.x matdyn.x plotband.x"
PSEUDO_LIST="Fe.pz-nd-rrkjus.UPF"

$ECHO
$ECHO "  executables directory: $BIN_DIR"
$ECHO "  pseudo directory:      $PSEUDO_DIR"
$ECHO "  temporary directory:   $TMP_DIR"
$ECHO "  checking that needed directories and files exist...\c"

# check for gnuplot
GP_COMMAND=`which gnuplot 2>/dev/null`
if [ "$GP_COMMAND" = "" ]; then
        $ECHO
        $ECHO "gnuplot not in PATH"
        $ECHO "Results will not be plotted"
fi

# check for directories
for DIR in "$BIN_DIR" "$PSEUDO_DIR" ; do
    if test ! -d $DIR ; then
        $ECHO
        $ECHO "ERROR: $DIR not existent or not a directory"
        $ECHO "Aborting"
        exit 1
    fi
done
for DIR in "$TMP_DIR" "$EXAMPLE_DIR/results" ; do
    if test ! -d $DIR ; then
        mkdir $DIR
    fi
done
cd $EXAMPLE_DIR/results

# check for executables
for FILE in $BIN_LIST ; do
    if test ! -x $BIN_DIR/$FILE ; then
        $ECHO
        $ECHO "ERROR: $BIN_DIR/$FILE not existent or not executable"
        $ECHO "Aborting"
        exit 1
    fi
done

# check for pseudopotentials
for FILE in $PSEUDO_LIST ; do
    if test ! -r $PSEUDO_DIR/$FILE ; then
       $ECHO
       $ECHO "Downloading $FILE to $PSEUDO_DIR...\c"
            $WGET $PSEUDO_DIR/$FILE $NETWORK_PSEUDO/$FILE 2> /dev/null
    fi
    if test $? != 0; then
        $ECHO
        $ECHO "ERROR: $PSEUDO_DIR/$FILE not existent or not readable"
        $ECHO "Aborting"
        exit 1
    fi
done
$ECHO " done"

# how to run executables
PW_COMMAND="$PARA_PREFIX $BIN_DIR/pw.x $PARA_POSTFIX"
PH_COMMAND="$PARA_PREFIX $BIN_DIR/ph.x $PARA_POSTFIX"
MATDYN_COMMAND="$PARA_PREFIX $BIN_DIR/matdyn.x $PARA_POSTFIX"
Q2R_COMMAND="$PARA_PREFIX $BIN_DIR/q2r.x $PARA_POSTFIX"
PLOTBAND_COMMAND="$BIN_DIR/plotband.x "
$ECHO
$ECHO "  running pw.x as:     $PW_COMMAND"
$ECHO "  running ph.x as:     $PH_COMMAND"
$ECHO "  running q2r.x as:    $Q2R_COMMAND"
$ECHO "  running matdyn.x as: $MATDYN_COMMAND"
$ECHO "  running plotband.x as: $PLOTBAND_COMMAND"
$ECHO "  running gnuplot as: $GP_COMMAND"
$ECHO

# clean TMP_DIR
$ECHO "  cleaning $TMP_DIR...\c"
rm -rf $TMP_DIR/fe*
rm -rf $TMP_DIR/_ph0/fe*
$ECHO " done"

# self-consistent calculation
cat > fe.scf.in << EOF
 &control
    calculation='scf'
    restart_mode='from_scratch',
    pseudo_dir = '$PSEUDO_DIR/',
    outdir='$TMP_DIR/',
    prefix='fe'
 /
 &system
    ibrav = 3, celldm(1) =5.217, nat= 1, ntyp= 1,
    ecutwfc = 25.0,ecutrho = 200.0,
    report=1,
    occupations='smearing', smearing='marzari-vanderbilt', degauss=0.05
    noncolin = .true.
    starting_magnetization(1) = 0.5
    angle1(1) = 90.0
    angle2(1) =  0.0
 /
 &electrons
    conv_thr = 1.0d-8
    mixing_beta = 0.2
 /
ATOMIC_SPECIES
 Fe 55.847 Fe.pz-nd-rrkjus.UPF
ATOMIC_POSITIONS
 Fe 0.0 0.0 0.0
K_POINTS
 11
   0.0625000  0.0625000  0.0625000   1.00
   0.0625000  0.0625000  0.1875000   3.00
   0.0625000  0.0625000  0.3125000   3.00
   0.0625000  0.0625000  0.4375000   3.00
   0.0625000  0.0625000  0.5625000   3.00
   0.0625000  0.0625000  0.6875000   3.00
   0.0625000  0.0625000  0.8125000   3.00
   0.0625000  0.0625000  0.9375000   3.00
   0.0625000  0.1875000  0.1875000   3.00
   0.0625000  0.1875000  0.3125000   6.00
   0.0625000  0.1875000  0.4375000   6.00
EOF
$ECHO "  running the scf calculation...\c"
$PW_COMMAND < fe.scf.in > fe.scf.out
check_failure $?
$ECHO " done"

# phonon calculation on a (444) uniform grid of q-points
cat > fe.ph.in << EOF
phonons of fe
 &inputph
     outdir ='$TMP_DIR/',
     prefix = 'fe',
     fildyn = 'fe.dyn',
     amass(1)=55.847,
     ldisp  = .true.,
     nq1 = 4,
     nq2 = 4,
     nq3 = 4,
     tr2_ph = 1.0d-14, 
    /
EOF
$ECHO "  running the phonon calculation ...\c"
$PH_COMMAND < fe.ph.in > fe.ph.out
check_failure $?
$ECHO " done"

cat > q2r.in <<EOF
 &input
   fildyn='fe.dyn', 
   zasr='simple', 
   flfrc='fe444.fc'
 /
EOF

$ECHO "  transforming C(q) => C(R)...\c"
$Q2R_COMMAND < q2r.in > q2r.out
check_failure $?
$ECHO " done"

cat > matdyn.in <<EOF
 &input
    asr='simple',  amass(1)=55.847,
    flfrc='fe444.fc', flfrq='fe.freq', q_in_band_form=.true.,
 /
8
  H     40
  P     40
  gG    40
  H     40
  N     40
  P     40
  N     40
  gG    10
EOF

$ECHO "  recalculating omega(q) from C(R)...\c"
$MATDYN_COMMAND < matdyn.in > matdyn.out
check_failure $?
$ECHO " done"

cat > plotband.in <<EOF
fe.freq
0 600
freq.plot
freq.ps
0.0
50.0 0.0
EOF

$ECHO "  writing the phonon dispersions in freq.plot...\c"
$PLOTBAND_COMMAND < plotband.in > /dev/null
check_failure $?
$ECHO " done"

if [ "$GP_COMMAND" = "" ]; then
    break
else
cat > gnuplot.tmp <<EOF
set encoding iso_8859_15
set terminal postscript enhanced solid color "Helvetica" 20
set output "fe.dispersions.ps"
#
set key off

set xrange [0:4.280239]
dim=450
set yrange [-250:dim]
set arrow from 1,0. to 1,dim nohead  lw 2
set arrow from 2,0. to 2,dim nohead  lw 2
set arrow from 1.5,0. to 1.5,dim nohead  lw 2
set arrow from 3.4142,0. to 3.4142,dim nohead  lw 2
set ylabel "frequency (cm^{-1})"
unset xtics
lpos=-15
set label "{/Symbol G}" at -0.05,lpos
set label "X" at 0.95,lpos
set label "W" at 1.45,lpos
set label "X" at 1.95,lpos
set label "{/Symbol G}" at 3.37,lpos
set label "L" at 4.1897,lpos

plot "freq.plot" u 1:2 w l lw 3  
EOF
$ECHO "  creating the postscript file fe.dispersion.ps...\c"
$GP_COMMAND gnuplot.tmp
check_failure $?
$ECHO " done"
fi


cat > phdos.in <<EOF
 &input
    asr='simple',  dos=.true. amass(1)=55.847,
    flfrc='fe444.fc', fldos='fe.phdos', nk1=6,nk2=6,nk3=6
 /
EOF

$ECHO "  calculating phonon DOS ...\c"
$MATDYN_COMMAND < phdos.in > phdos.out
check_failure $?
$ECHO " done"

if [ "$GP_COMMAND" = "" ]; then
    break
else
cat > gnuplot1.tmp <<EOF
set encoding iso_8859_15
set terminal postscript enhanced solid color "Helvetica" 20
set output "fe.phdos.ps"
#
set key off
set xrange [0:450]
set xlabel "frequency (cm^{-1})"
set ylabel "DOS"
plot 'fe.phdos' u 1:2 w l lw 3 
EOF
$ECHO "  generating plot of phonon_dos in the file fe.phdos.ps...\c"
$GP_COMMAND  gnuplot1.tmp
check_failure $?
$ECHO " done"
fi

$ECHO
$ECHO "$EXAMPLE_DIR: done"