#! /bin/sh

# The (scalar) ZORA relativistic option formalism) is used because of the
# presence of the heavy Pt atom. The complex is built from fragments H2 and
# PtCl_4^2- .

# The calculations of the molecule and larger fragments are performed with
# GGA's.


# == fragments H2 and PtCl_4^2- ==

# The two fragments H2 and PtCl_4^2- are first calculated, from which we are
# going to build the final complex.


$ADFBIN/adf <<eor
Title   H2  R=1.68a.u.
NoPrint sfo,frag,functions
Units
  length bohr
End
Atoms
  H       0.0             0.0             0.84
  H       0.0             0.0            -0.84
End
Basis
  Type DZP
End
XC
  GGA  becke perdew
End
Relativistic Scalar ZORA
eor

mv TAPE21 H2.t21
rm logfile


$ADFBIN/adf <<eor
title   PtCl4 (2-)
noprint sfo,frag,functions
units
  length   bohr
end
ATOMS
  Pt    0           0          0
  Cl    4.361580    0.000000   0
  Cl    0.000000    4.361580   0
  Cl   -4.361580    0.000000   0
  Cl    0.000000   -4.361580   0
end

Basis
  Type DZP
  Pt ZORA/DZ/Pt.4d
End
xc
  GGA  becke perdew
end
relativistic scalar ZORA
charge  -2
eor

mv TAPE21 PtCl4.t21
rm logfile

# The key charge is used to specify the net total charge. The default for the
# net total charge is the sum-of-fragment-charges. The fragments (Pt and Cl
# atoms) have been computed neutrally, but we want to calculate the PtCl4
# complex as a 2- ion.


# == Main calculation ==

# Finally we compute PtCl4 H2 2- from the fragments PtCl_4^2- and H2/


$ADFBIN/adf <<eor
title   PtCl4 H2
units
  length bohr
end
EPRINT
  SFO eig ovl
END
xc
  GGA  becke perdew
end
relativistic scalar ZORA
ATOMS
  Pt   0             0             0             f=PtCl4
  Cl   0.000000     -4.361580      0.00000000    f=PtCl4
  Cl   0.000000      4.361580      0.00000000    f=PtCl4
  Cl  -4.361580      0.000000      0.00000000    f=PtCl4
  Cl   4.361580      0.000000      0.00000000    f=PtCl4
  H    0.0           0.0           5.58          f=H2
  H    0.0           0.0           7.26          f=H2
end
fragments
  PtCl4     PtCl4.t21
  H2        H2.t21
end
eor

mv TAPE21 PtCl4H2.t21


# Note that, although the key charge is not supplied, the molecule is not
# neutral: the default charge (that is, omitting the keys charge, occupations)
# is the sum-of-fragments: the fragments here are H2 and PtCl4 2- , yielding a
# net charge for the molecule of minus two.

# Note the f=fragment specification in the Atoms block. No fragment-numbering
# suffix (/n) is required because there is only one fragment of each fragment
# type.