#!/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 the phonon dispersion on a GRID"
$ECHO "for AlAs in zincblende structure. Only q-points are split."

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

# required executables and pseudopotentials
BIN_LIST="pw.x ph.x q2r.x matdyn.x"
PSEUDO_LIST="Al.pz-vbc.UPF As.pz-bhs.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 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_1" ; do
    if test ! -d $DIR ; then
        mkdir $DIR
    fi
done
cd $EXAMPLE_DIR/results_1

# 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 "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 $PARA_POSTFIX"
Q2R_COMMAND="$PARA_PREFIX $BIN_DIR/q2r.x $PARA_POSTFIX"
MATDYN_COMMAND="$PARA_PREFIX $BIN_DIR/matdyn.x $PARA_POSTFIX"
$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

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

# self-consistent calculation
cat > alas.scf.in << EOF
 &control
    calculation='scf'
    restart_mode='from_scratch',
    tstress = .true.
    tprnfor = .true.
    prefix='alas',
    pseudo_dir = '$PSEUDO_DIR/',
    outdir='$TMP_DIR/'
 /
 &system
    ibrav=  2, celldm(1) =10.50, nat=  2, ntyp= 2,
    ecutwfc =16.0
 /
 &electrons
    conv_thr =  1.0d-8
    mixing_beta = 0.7
 /
ATOMIC_SPECIES
 Al  26.98  Al.pz-vbc.UPF
 As  74.92  As.pz-bhs.UPF
ATOMIC_POSITIONS
 Al 0.00 0.00 0.00
 As 0.25 0.25 0.25
K_POINTS
 2
 0.25 0.25 0.25 1.0
 0.25 0.25 0.75 3.0
EOF
$ECHO "  running the scf calculation...\c"
$PW_COMMAND < alas.scf.in > alas.scf.out
check_failure $?
$ECHO " done"

for q in `seq 1 8 ` ; do

cat > input.$q << EOF
phonons of AlAs
 &inputph
  tr2_ph=1.0d-12,
  prefix='alas',
  ldisp=.true.,
  nq1=4, nq2=4, nq3=4
  start_q=$q
  last_q=$q
  recover=.true.,
  amass(1)=26.98,
  amass(2)=74.92,
  outdir="$TMP_DIR/$q",
  fildyn='alas.dyn',
 /
EOF

mkdir $TMP_DIR/$q
cp -r $TMP_DIR/alas.* $TMP_DIR/$q

$ECHO "  running the phonon calculation for q= " $q " ...\c"
$PH_COMMAND < input.$q > output.$q
$ECHO " done"

done
#
# Please note: if the previous step was done in different machines
# here you should copy all the dynamical matrices in the same directory
# in which you run q2r.x
#

cat > q2r.in <<EOF
 &input
   fildyn='alas.dyn', zasr='simple', flfrc='alas444.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)=26.98, amass(2)=74.922,
    flfrc='alas444.fc', flfrq='alas.freq'
 /
 9
  0.000 0.0 0.0  0.0
  0.125 0.0 0.0  0.0
  0.250 0.0 0.0  0.0
  0.375 0.0 0.0  0.0
  0.500 0.0 0.0  0.0
  0.625 0.0 0.0  0.0
  0.750 0.0 0.0  0.0
  0.875 0.0 0.0  0.0
  1.000 0.0 0.0  0.0
EOF

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

cat > phdos.in <<EOF
 &input
    asr='simple',  dos=.true. amass(1)=26.98, amass(2)=74.922,
    flfrc='alas444.fc', fldos='alas.phdos', nk1=6,nk2=6,nk3=6
 /
EOF

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

$ECHO
$ECHO "$EXAMPLE_DIR: done"

