Example: Charge transfer integrals with FOCDFT
**********************************************

"Download Ethylene_FOCDFT.run"

   #! /bin/sh

   # FOCDFT is used to calculate charge transfer integrals
   # for the ethylene dimer using PBE and an all electron DZ basis set.
   # The influence of othere ethylenes in the environment is investigated.

   # FOCDFT is a fragment orbital based method for constraining (integer) charges and spins on fragments.
   # It uses the (localized) Lowdins that ADF makes to to constrain charges and spins on fragments.
   # This method can be used to specify 2 different electron configurations of the same complex,
   # such that a charge on the first fragment in the first calculation is transferred
   # to the second fragment in the second calculation.

   # Because in the final complexes the ethylene molecules are the same,
   # only one fragment needs to be calculated.

   AMS_JOBNAME=Frag $AMSBIN/ams <<eor
   System
     symmetrize
     atoms
       C      0.000000    0.000000    0.000000
       C      1.332000    0.000000    0.000000
       H     -0.574301    0.000000   -0.928785
       H     -0.574301    0.000000    0.928785
       H      1.906301    0.000000    0.928785
       H      1.906301    0.000000   -0.928785
     end
   end

   Task SinglePoint

   Engine ADF
     basis
       Type DZ
       core none
     end
     xc
       gga pbe
     end
   EndEngine
   eor

   # Charge transfer integrals for the ethylene dimer at a distance of 4 Angstrom.

   AMS_JOBNAME=ET2_4 $AMSBIN/ams <<eor
   System
     symmetrize
     atoms
       C      0.000000    0.000000    0.000000 adf.f=Frag1
       C      1.332000    0.000000    0.000000 adf.f=Frag1
       H     -0.574301    0.000000   -0.928785 adf.f=Frag1
       H     -0.574301    0.000000    0.928785 adf.f=Frag1
       H      1.906301    0.000000    0.928785 adf.f=Frag1
       H      1.906301    0.000000   -0.928785 adf.f=Frag1
       C     -0.000000    4.000000    0.000000 adf.f=Frag2
       C      1.332000    4.000000   -0.000000 adf.f=Frag2
       H     -0.574301    4.000000    0.928785 adf.f=Frag2
       H     -0.574301    4.000000   -0.928785 adf.f=Frag2
       H      1.906301    4.000000   -0.928785 adf.f=Frag2
       H      1.906301    4.000000    0.928785 adf.f=Frag2
     end
     charge 1
   end

   Task SinglePoint

   Engine ADF
     fragments
        Frag1 Frag.results/adf.rkf
        Frag2 Frag.results/adf.rkf
     end
     spinpolarization 1
     unrestricted
     xc
       gga pbe
     end
     FOCDFT
       charge 1 0
       spinpolarization 1 0
       electrontransfer
         charge 0 1
         spinpolarization 0 1
       end
     end
   EndEngine
   eor

   # Charge transfer integrals for the ethylene dimer at a distance of 8 Angstrom.
   # The calculated charge transfer integral will be much smaller than that of the previous calculation
   # where the two ethylene molecules were at a distance of 4 Angstrom.

   AMS_JOBNAME=ET2_8 $AMSBIN/ams <<eor
   System
     symmetrize
     atoms
       C      0.000000    0.000000    0.000000 adf.f=Frag1
       C      1.332000    0.000000    0.000000 adf.f=Frag1
       H     -0.574301    0.000000   -0.928785 adf.f=Frag1
       H     -0.574301    0.000000    0.928785 adf.f=Frag1
       H      1.906301    0.000000    0.928785 adf.f=Frag1
       H      1.906301    0.000000   -0.928785 adf.f=Frag1
       C     -0.000000    8.000000    0.000000 adf.f=Frag3
       C      1.332000    8.000000   -0.000000 adf.f=Frag3
       H     -0.574301    8.000000    0.928785 adf.f=Frag3
       H     -0.574301    8.000000   -0.928785 adf.f=Frag3
       H      1.906301    8.000000   -0.928785 adf.f=Frag3
       H      1.906301    8.000000    0.928785 adf.f=Frag3
     end
     charge 1
   end

   Task SinglePoint

   Engine ADF
     fragments
        Frag1 Frag.results/adf.rkf
        Frag3 Frag.results/adf.rkf
     end
     spinpolarization 1
     unrestricted
     xc
       gga pbe
     end
     FOCDFT
       charge 1 0
       spinpolarization 1 0
       electrontransfer
         charge 0 1
         spinpolarization 0 1
       end
     end
   EndEngine
   eor

   # Charge transfer integrals for the ethylene dimer at a distance of 8 Angstrom,
   # with another ethylene molecule exactly in between.
   # The calculated charge transfer integral will be significant larger than that of the previous calculation
   # where there was no other ethylene molecule in between.

   AMS_JOBNAME=ET3 $AMSBIN/ams <<eor
   System
     symmetrize
     atoms
       C      0.000000    0.000000    0.000000 adf.f=Frag1
       C      1.332000    0.000000    0.000000 adf.f=Frag1
       H     -0.574301    0.000000   -0.928785 adf.f=Frag1
       H     -0.574301    0.000000    0.928785 adf.f=Frag1
       H      1.906301    0.000000    0.928785 adf.f=Frag1
       H      1.906301    0.000000   -0.928785 adf.f=Frag1
       C     -0.000000    4.000000    0.000000 adf.f=Frag2
       C      1.332000    4.000000   -0.000000 adf.f=Frag2
       H     -0.574301    4.000000    0.928785 adf.f=Frag2
       H     -0.574301    4.000000   -0.928785 adf.f=Frag2
       H      1.906301    4.000000   -0.928785 adf.f=Frag2
       H      1.906301    4.000000    0.928785 adf.f=Frag2
       C      0.000000    8.000000    0.000000 adf.f=Frag3
       C      1.332000    8.000000    0.000000 adf.f=Frag3
       H     -0.574301    8.000000   -0.928785 adf.f=Frag3
       H     -0.574301    8.000000    0.928785 adf.f=Frag3
       H      1.906301    8.000000    0.928785 adf.f=Frag3
       H      1.906301    8.000000   -0.928785 adf.f=Frag3
     end
     charge 1
   end

   Task SinglePoint

   Engine ADF
     fragments
        Frag1 Frag.results/adf.rkf
        Frag2 Frag.results/adf.rkf
        Frag3 Frag.results/adf.rkf
     end
     spinpolarization 1
     unrestricted
     xc
       gga pbe
     end
     FOCDFT
       charge 1 0 0
       spinpolarization 1 0 0
       electrontransfer
         charge 0 0 1
         spinpolarization 0 0 1
       end
     end
   EndEngine
   eor

   # Charge transfer integrals for the ethylene dimer at a distance of 4 Angstrom,
   # with 2 ethylene molecules on either side of the dimer.
   # In this case the calculated charge transfer integral will not be very different
   # than that for the isolated dimer at 4 Angstrom.

   AMS_JOBNAME=ET4 $AMSBIN/ams <<eor
   System
     symmetrize
     atoms
       C     -0.000000   -4.000000    0.000000 adf.f=Frag0
       C      1.332000   -4.000000   -0.000000 adf.f=Frag0
       H     -0.574301   -4.000000    0.928785 adf.f=Frag0
       H     -0.574301   -4.000000   -0.928785 adf.f=Frag0
       H      1.906301   -4.000000   -0.928785 adf.f=Frag0
       H      1.906301   -4.000000    0.928785 adf.f=Frag0
       C      0.000000    0.000000    0.000000 adf.f=Frag1
       C      1.332000    0.000000    0.000000 adf.f=Frag1
       H     -0.574301    0.000000   -0.928785 adf.f=Frag1
       H     -0.574301    0.000000    0.928785 adf.f=Frag1
       H      1.906301    0.000000    0.928785 adf.f=Frag1
       H      1.906301    0.000000   -0.928785 adf.f=Frag1
       C     -0.000000    4.000000    0.000000 adf.f=Frag2
       C      1.332000    4.000000   -0.000000 adf.f=Frag2
       H     -0.574301    4.000000    0.928785 adf.f=Frag2
       H     -0.574301    4.000000   -0.928785 adf.f=Frag2
       H      1.906301    4.000000   -0.928785 adf.f=Frag2
       H      1.906301    4.000000    0.928785 adf.f=Frag2
       C      0.000000    8.000000    0.000000 adf.f=Frag3
       C      1.332000    8.000000    0.000000 adf.f=Frag3
       H     -0.574301    8.000000   -0.928785 adf.f=Frag3
       H     -0.574301    8.000000    0.928785 adf.f=Frag3
       H      1.906301    8.000000    0.928785 adf.f=Frag3
       H      1.906301    8.000000   -0.928785 adf.f=Frag3
     end
     charge 1
   end

   Task SinglePoint

   Engine ADF
     fragments
        Frag0 Frag.results/adf.rkf
        Frag1 Frag.results/adf.rkf
        Frag2 Frag.results/adf.rkf
        Frag3 Frag.results/adf.rkf
     end
     spinpolarization 1
     unrestricted
     xc
       gga pbe
     end
     FOCDFT
       charge 0 1 0 0
       spinpolarization 0 1 0 0
       electrontransfer
         charge 0 0 1 0
         spinpolarization 0 0 1 0
       end
     end
   EndEngine
   eor
