#!/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 and pw2bgw.x toproduce files "
$ECHO "for usage by BerkeleyGW."

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

# required executables and pseudopotentials
BIN_LIST="pw.x pw2bgw.x"
PSEUDO_LIST="Si.bhs"

$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 $PARA_POSTFIX"
PW2BGW_COMMAND="$PARA_PREFIX $BIN_DIR/pw2bgw.x $PARA_POSTFIX"
$ECHO
$ECHO "  running pw.x as:       $PW_COMMAND"
$ECHO "  running pw2bgw.x as:   $PW2BGW_COMMAND"
$ECHO

# self-consistent calculation
cat > si.scf.in << EOF
&control
   prefix = 'si'
   calculation = 'scf'
   verbosity = 'high'
   tstress = .true.
   tprnfor = .true.
    restart_mode='from_scratch',
    pseudo_dir = '$PSEUDO_DIR/',
    outdir='$TMP_DIR/'
 /
&system
   ibrav = 0
   a = 5.43
   nat = 2
   ntyp = 1
   nbnd = 33
   ecutwfc = 45.0
   occupations = 'smearing'
   smearing = 'mp'
   degauss = 0.01
/
&electrons
   electron_maxstep = 100
   conv_thr = 1.0d-10
   mixing_mode = 'plain'
   mixing_beta = 0.7
   mixing_ndim = 8
   diagonalization = 'david'
   diago_david_ndim = 4
   diago_full_acc = .true.
   startingwfc = 'random'
/
CELL_PARAMETERS alat
       0.000000000   0.500000000   0.500000000
       0.500000000   0.000000000   0.500000000
       0.500000000   0.500000000   0.000000000
ATOMIC_SPECIES
  Si  28.086  Si.bhs
ATOMIC_POSITIONS crystal
  Si  -0.125000000  -0.125000000  -0.125000000
  Si   0.125000000   0.125000000   0.125000000
K_POINTS automatic
8 8 8 0 0 0
EOF
$ECHO "  running the scf calculation...\c"
$PW_COMMAND < si.scf.in > si.scf.out
check_failure $?
$ECHO " done"

# pw2bgw
cat > si.pw2bgw.in << EOF

&input_pw2bgw
   prefix = 'si'
   outdir='$TMP_DIR/'
   real_or_complex = 1
   wfng_flag = .true.
   wfng_file = 'WFN'
   wfng_kgrid = .true.
   wfng_nk1 = 8
   wfng_nk2 = 8
   wfng_nk3 = 8
   wfng_dk1 = 0.0
   wfng_dk2 = 0.0
   wfng_dk3 = 0.0
   rhog_flag = .true.
   rhog_file = 'RHO'
   vxcg_flag = .true.
   vxcg_file = 'VXC'
   vxc0_flag = .true.
   vxc0_file = 'vxc0.dat'
   vxc_flag = .true.
   vxc_file = 'vxc.dat'
   vxc_integral = 'g'
   vxc_diag_nmin = 1
   vxc_diag_nmax = 33
   vxc_offdiag_nmin = 0
   vxc_offdiag_nmax = 0
   vxc_zero_rho_core = .true.
   vscg_flag = .true.
   vscg_file = 'VSC'
   vkbg_flag = .true.
   vkbg_file = 'VKB'
/
EOF
$ECHO "  running pw2bgw.x to save files for BerkeleyGW...\c"
$PW2BGW_COMMAND < si.pw2bgw.in > si.pw2bgw.out
check_failure $?
$ECHO " done"

mv $TMP_DIR/vxc* ./

$ECHO "  cleaning $TMP_DIR...\c"
rm -rf $TMP_DIR/si.* $TMP_DIR/???

$ECHO
$ECHO "$EXAMPLE_DIR: done"
