#!/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 (a water molecule) shows how to use cp.x to perform"
$ECHO "molecular dynamics with variable parameters using AUTOPILOT."
$ECHO "The variables are changed without stopping and starting cp.x."
$ECHO "For example the dt value can be changed from 3 to 5 to 10 to 15"
$ECHO "at predefined time steps. For other advanced options like STRING"
$ECHO "(send a signal to a running cp.x process to change some parameter"
$ECHO "on the fly) or Pause please consult the AUTOPILOT documentation."

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

# required executables and pseudopotentials
BIN_LIST="cp.x"
PSEUDO_LIST="H_US.van O_US.van"

$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 "ERROR: $PSEUDO_DIR/$FILE not existent or not readable"
        $ECHO "Aborting"
        exit 1
    fi
done
$ECHO " done"

# how to run executables
CP_COMMAND="$PARA_PREFIX $BIN_DIR/cp.x $PARA_POSTFIX"
$ECHO
$ECHO "  running cp.x as: $CP_COMMAND"
$ECHO

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

# molecular dynamics calculation
cat > water.autopilot.in << EOF
  &CONTROL
    calculation='cp',
    title="WATER",
    restart_mode='from_scratch',
    nstep=10000, iprint=30, isave=30,
    tstress=.FALSE.,
    tprnfor=.FALSE.,
    dt = 3.,
    ndr=90,
    ndw=91,
    ekin_conv_thr=1e-09
    pseudo_dir='$PSEUDO_DIR/',
    outdir='$TMP_DIR/',
  /
  &SYSTEM
    ibrav = 1,
    celldm(1) = 10.,
    nat =3,
    ntyp =2,
    nbnd =4,
    ecutwfc =25.0,
    ecutrho =200.0,
    nr1b=20, nr2b=20, nr3b=20,
    occupations = 'fixed',
    nspin=1,
    ecfixed =25.0
  /
  &ELECTRONS
    emass = 700.,
    emass_cutoff = 3.,
    orthogonalization = 'ortho',
    electron_maxstep = 200,
    ortho_eps = 1.e-10,
    ortho_max = 250,
    electron_dynamics= 'damp',
    electron_damping =0.15,
    startingwfc='random'
    ampre=0.02
  /
  &IONS
    ion_dynamics    = 'none',
    ion_radius      = 1.0,
    ion_damping     = 0.0,
    ion_positions   = 'default',
    ion_temperature = 'not_controlled',
    tempw=800,
    fnosep=37.22179
  /
AUTOPILOT
    on_step =  31  : dt=5
    on_step =  61  : dt=10
    on_step =  91  : dt=15
    on_step =  91  : iprint=100
    on_step =  91  : isave=100
    on_step = 191  : ion_dynamics    = 'damp'
    on_step = 191  : electron_damping =0.00
    on_step = 191  : isave=500
    on_step = 191  : isave=500
    on_step = 691  : ion_temperature = 'nose'
    on_step = 691  : tempw=150
    on_step = 1191 : tempw=300
    on_step = 1691 : tempw=500
    on_step = 2191 : iprint=50
    on_step = 2191 : isave=50
    on_step = 2191 : electron_damping = 0.10
    on_step = 2191 : ion_dynamics = 'none'
    on_step = 2191 : ion_temperature ='not_controlled'
    on_step = 2241 : iprint=200
    on_step = 2241 : isave=200
    on_step = 2241 : electron_damping =0.00
    on_step = 2241 : ion_dynamics    = 'damp'
    on_step = 2441 : iprint=900
    on_step = 2441 : isave=500
    on_step = 2441 : electron_damping =0.15
    on_step = 2441 : ion_temperature = 'nose'
    on_step = 2441 : tempw=800
    on_step = 3341 : iprint=200
    on_step = 3341 : isave=200
    on_step = 3341 : electron_damping =0.00
    on_step = 3541 : iprint=50
    on_step = 3541 : isave=50
    on_step = 3541 : ion_dynamics    = 'none'
    on_step = 3541 : ion_temperature = 'not_controlled'
    on_step = 3591 : iprint=2000
    on_step = 3591 : isave=2000
    on_step = 3591 : ion_dynamics    = 'damp'
    on_step = 3591 : ion_temperature = 'nose'
    on_step = 6591 : iprint=10000
    on_step = 6591 : isave=500
    on_step = 6591 : electron_damping =0.00
    on_step = 6591 : ion_temperature = 'nose'
ENDRULES
ATOMIC_SPECIES
 H   1.00794000    H_US.van 
 O  15.99940000    O_US.van
ATOMIC_POSITIONS {bohr}
 H     0.57164238	  0.94335166	  0.96565043
 H    -0.24339682	 -0.43501513	 -1.37874473
 O    -0.32824556	 -0.50852550	  0.41309430
EOF
$ECHO "  running CP  calculation with AUTOPILOT option...\c"
$CP_COMMAND < water.autopilot.in > water.autopilot.out
$ECHO " done"
exit 0