#! /bin/sh

# A bulk crystal computation for Sodium Chloride (common salt), with a
# subsequent DOS analysis, using a Restart facility to use the results from a
# preceding calculation.

# The BAND input follows slightly different conventions from the ADF input, for
# historical reasons.

# Since there are 3 data records in the Lattice block, the calculation will
# assume 3-dimensional periodicity, with lattice vectors as indicated. Note that
# lattice vectors are undefined up to linear combinations among themselves.
# Internally, the program will recombine the input vectors so as to minimize the
# size of the actually used vectors.

# The input line FractionalCoords True means that atomic positions are input as
# coefficients in terms of the lattice vectors, rather than as absolute
# (Cartesian) coordinate values.

AMS_JOBNAME=NaCl $AMSBIN/ams <<eor

Task SinglePoint

System
  FractionalCoords True

  Atoms
    Na 0.0 0.0 0.0
    Cl 0.5 0.5 0.5 
  End

  Lattice    
    0.0   2.75   2.75   
    2.75  0.0    2.75   
    2.75  2.75   0.0    
  End
End

Engine Band
  Title NaCl

  Kspace
    Symmetric KInteg=3
  End

  Basis
    Type SZ
    Core None
  End

  Print AtomicChargesDetails

EndEngine

eor

# The next run has largely the same input and provides a restart of the previous
# run.

# The key DOS in the block Restart tells the program to pick up the indicated
# file as restart file and to use it for DOS analysis purposes.

# The DOS key block details the energy grid (and range) and the file to write
# the data to. The optional keys GROSSPOPULATIONS and OverlapPopulations invoke
# the computation of, respectively, gross populations and overlap populations
# (i.e. for each of these the density-of-states values in the user-defined
# energy grid).

AMS_JOBNAME=NaCl-restart $AMSBIN/ams <<eor

Task SinglePoint

LoadSystem
  File NaCl.results/ams.rkf
  Section InputMolecule
End

Engine Band
  Title NaCl DOS analysis (restart)

  Kspace
    Symmetric KInteg=3
  End

  Basis
    Type SZ
    Core None
  End

  Restart
    File NaCl.results/band.rkf
    SCF
  End

  DOS
    CalcPDos  True
    File      NaCl.dos
    Energies  1000
    Min      -0.5
    Max       0.5
  End

  GrossPopulations
   FRAG 1
   FRAG 2
   SUM
     1 0
     2 0
   ENDSUM
  End

  OverlapPopulations
  Left
   FRAG 1
  Right
   FRAG 2
  Left
    1 0
    1 1
  Right
    2 0
    2 1
  End

  Print AtomicChargesDetails
EndEngine
eor

# Finally, we copy the contents of the DOS result file to standard output

echo ""
echo Contents of DOS file
cat NaCl.dos