#!/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 use pw.x head.x pw4gww.x gww. x to calculate"
$ECHO "the GW QP levels of bulk Si"

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

# required executables and pseudopotentials
BIN_LIST="pw.x head.x pw4gww.x gww.x"
PSEUDO_LIST="Si.pz-vbc.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 "
$ECHO
$ECHO "  running pw.x as: $PW_COMMAND"
$ECHO
HEAD_COMMAND="$PARA_PREFIX $BIN_DIR/head.x "
$ECHO
$ECHO "  running pw.x as: $HEAD_COMMAND"
$ECHO
PW4GWW_COMMAND="$PARA_PREFIX $BIN_DIR/pw4gww.x "
$ECHO
$ECHO "  running pw4gww.x as: $PW4GWW_COMMAND"
$ECHO
GWW_COMMAND="$PARA_PREFIX $BIN_DIR/gww.x "
$ECHO
$ECHO "  running gww.x as: $GWW_COMMAND"
$ECHO


    # self-consistent calculation
    cat > si_scf_k.in << EOF
&control
 calculation='scf'
 restart_mode='from_scratch',
 prefix='si'
 pseudo_dir = '$PSEUDO_DIR/',
 outdir='$TMP_DIR/'
/
&system
 ibrav= 8, celldm(1)= 10.26,celldm(2)= 1, celldm(3)=1,
 nat=  8, ntyp= 1,
 ecutwfc = 15.0
/
&electrons
 diagonalization='david',
 conv_thr =  1.0d-10,
 mixing_beta = 0.5,
 startingwfc='random',
/
ATOMIC_SPECIES
Si  1. Si.pz-vbc.UPF
ATOMIC_POSITIONS (crystal)
Si 0.00000 0.00000 0.00000
Si 0.50000 0.50000 0.00000
Si 0.00000 0.50000 0.50000
Si 0.50000 0.00000 0.50000
Si 0.25000 0.25000 0.25000
Si 0.75000 0.75000 0.25000
Si 0.75000 0.25000 0.75000
Si 0.25000 0.75000 0.75000
K_POINTS (automatic)
4 4 4 1 1 1

EOF
    $ECHO "  running the scf calculation for Si...\c"
    $PW_COMMAND < si_scf_k.in > si_scf_k.out
    check_failure $?
    $ECHO " done"

    #calculation of head 
    cat > si_head.in << EOF
calculation of head
 &inputph
  trans=.false.
  l_head=.true.
  tr2_ph=1.d-4,
  prefix='si',
  omega_gauss=20.0
  n_gauss=97
  grid_type=5
  second_grid_i=1
  second_grid_n=10
  niter_ph=1
  nsteps_lanczos=30
  outdir='$TMP_DIR/'
 /
0.0 0.0 0.0

EOF
    $ECHO "  running the head calculation for Si...\c"
    $HEAD_COMMAND < si_head.in > si_head.out
    check_failure $?
    $ECHO " done"

    # non self-consistent calculation
    cat > si_nscf.in << EOF
&control
 calculation='nscf'
 restart_mode='from_scratch',
 prefix='si'
 pseudo_dir = '$PSEUDO_DIR/',
 outdir='$TMP_DIR/'
/
&system
 ibrav= 8, celldm(1)= 10.26,celldm(2)= 1, celldm(3)=1,
 nat=  8, ntyp= 1,
 ecutwfc = 15.0,nbnd=32
/
&electrons
 diagonalization='david',
 conv_thr =  1.0d-10,
 mixing_beta = 0.5,
 startingwfc='random',
/
ATOMIC_SPECIES
Si  1. Si.pz-vbc.UPF
ATOMIC_POSITIONS (crystal)
Si 0.00000 0.00000 0.00000
Si 0.50000 0.50000 0.00000
Si 0.00000 0.50000 0.50000
Si 0.50000 0.00000 0.50000
Si 0.25000 0.25000 0.25000
Si 0.75000 0.75000 0.25000
Si 0.75000 0.25000 0.75000
Si 0.25000 0.75000 0.75000
K_POINTS (gamma)

EOF
    $ECHO "  running the nscf calculation for Si...\c"
    $PW_COMMAND < si_nscf.in > si_nscf.out
    check_failure $?
    $ECHO " done"



    #pw4gww calculations 
    cat > si_pw4gww.in << EOF
&inputpw4gww    
    prefix='si'
    num_nbndv(1)=16
    num_nbnds=32
    l_truncated_coulomb=.false.
    numw_prod=100
    pmat_cutoff=3d0
    s_self_lanczos=1d-8
    outdir='$TMP_DIR'
/


EOF
    $ECHO "  running the pw4gww calculation for Si...\c"
    $PW4GWW_COMMAND < si_pw4gww.in > si_pw4gww.out
    check_failure $?
    $ECHO " done"


  cat > si_gww.in << EOF
&inputgww
ggwin%prefix='si'
ggwin%n=97,
ggwin%n_fit=120,
ggwin%max_i=32,
ggwin%i_min=1
ggwin%i_max=32
ggwin%l_truncated_coulomb=.false.
ggwin%grid_time=3
ggwin%grid_freq=5
ggwin%second_grid_i=1
ggwin%second_grid_n=10
ggwin%omega=20
ggwin%omega_fit=20
ggwin%n_grid_fit=240
ggwin%tau=9.8
ggwin%n_set_pola=16
ggwin%outdir='$TMP_DIR'
/

EOF

    $ECHO "  running the gww calculation for Si...\c"
    $GWW_COMMAND < si_gww.in > si_gww.out
    check_failure $?
    $ECHO " done"

    #copy self_energy files
    $ECHO  "copying self-energy files..\c"
    cp $TMP_DIR/si-im_on_im* .
    cp $TMP_DIR/si-re_on_im* .
	 

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

$ECHO
$ECHO "$EXAMPLE_DIR : done"