#!/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 produce a model hamiltonian in Wannier "
$ECHO "functions basis. The system under consideration is Nickel oxide"

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

# required executables and pseudopotentials
BIN_LIST="pw.x wannier_ham.x"
PSEUDO_LIST="O.pz-rrkjus.UPF Ni.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 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 $PARA_POSTFIX"
HAM_COMMAND="$BIN_DIR/wannier_ham.x"
$ECHO
$ECHO "  running pw.x as: $PW_COMMAND"
$ECHO "  running wannier_ham.x as: $HAM_COMMAND"
$ECHO

# self-consistent calculation
cat > NiO.scf.in << EOF
    &control
     calculation = 'scf'
     prefix='NiO',
     pseudo_dir = '$PSEUDO_DIR/',
     outdir='$TMP_DIR/',
    /
    &system
     ibrav=0, celldm(1)=7.92664836, 
     nat=2, ntyp=2,
     ecutwfc = 45.0, 
     occupations='smearing',
     degauss = 0.01
     nbnd=11
    /
    &electrons
     conv_thr =  1.0d-5
    /
    CELL_PARAMETERS
     0.0 0.5 0.5
     0.5 0.0 0.5
     0.5 0.5 0.0
    ATOMIC_SPECIES
     Ni  1.  Ni.pz-nd-rrkjus.UPF
     O   1.  O.pz-rrkjus.UPF
    ATOMIC_POSITIONS crystal
     Ni 0.00 0.00 0.00
     O 0.50 0.50 0.50
    K_POINTS automatic
     4 4 4 0 0 0
EOF
$ECHO "  running the scf calculation for NiO...\c"
$PW_COMMAND < NiO.scf.in > NiO.scf.out
check_failure $?
$ECHO " done"
    
# nscf calculation
cat > NiO.nscf.in << EOF
    &control
     calculation = 'nscf'
     prefix='NiO',
     pseudo_dir = '$PSEUDO_DIR/',
     outdir='$TMP_DIR/',
     wf_collect=.true.
    /
    &system
     ibrav=0, celldm(1)=7.92664836, 
     nat=2, ntyp=2,
     ecutwfc = 45.0, 
     occupations='smearing',
     degauss = 0.01
     nosym = .true.
     noinv = .true.
     nbnd=11
    /
    &electrons
    /
    CELL_PARAMETERS
     0.0 0.5 0.5
     0.5 0.0 0.5
     0.5 0.5 0.0
    ATOMIC_SPECIES
     Ni  1.  Ni.pz-nd-rrkjus.UPF
     O   1.  O.pz-rrkjus.UPF
    ATOMIC_POSITIONS crystal
     Ni 0.00 0.00 0.00
     O 0.50 0.50 0.50
    K_POINTS automatic
     12 12 12 0 0 0
EOF
    $ECHO "  running the nscf calculation for NiO...\c"
    $PW_COMMAND < NiO.nscf.in > NiO.nscf.out
    check_failure $?
    $ECHO " done"

cat > wannier_hamilt.in << EOF
&inputpp
 prefix='NiO'
 outdir='$TMP_DIR/'
 nwan = 8
/
WANNIER_AC
 Wannier# 1 2 9
 atom 1
 d 1 1.0
 Wannier# 2 2 9
 atom 1
 d 2 1.0
 Wannier# 3 2 9
 atom 1
 d 3 1.0
 Wannier# 4 2 9
 atom 1
 d 4 1.0
 Wannier# 5 2 9
 atom 1
 d 5 1.0
 Wannier# 6 2 9
 atom 2
 p 1 1.0
 Wannier# 7 2 9
 atom 2
 p 2 1.0
 Wannier# 8 2 9
 atom 2
 p 3 1.0
EOF
$ECHO "  running the hamiltonian generation...\c"
$HAM_COMMAND < wannier_hamilt.in > wannier_hamilt.out
$ECHO " done"

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

$ECHO
$ECHO "$EXAMPLE_DIR : done"