Example: Constraint Geometry Optimization: H2O
**********************************************

"Download GO_constraints.run"

   #! /bin/sh

   # The key Constraints can only be used to enforce constraint in a geometry
   # optimization. The Constraints do not have to be satisfied at the start
   # of the geometry optimization.


   # == Example for angle constraint for water ==


   AMS_JOBNAME=angle $AMSBIN/ams <<eor

   System
       Atoms
           O         0.001356    0.000999    0.000000
           H         0.994442   -0.037855    0.000000
           H        -0.298554    0.948531    0.000000
       End
   End

   Task GeometryOptimization

   GeometryOptimization
      Convergence Step=1.0e-3
   End

   Constraints
     Angle 3 1 2 125.0
   End

   Engine ADF
       Basis
           Type DZP
       End
   EndEngine
   eor

   echo "Angle after optimization:"
   $AMSBIN/amsreport angle.results/adf.rkf -r angle#3#1#2


   # == Example for fixed-coordinates constraint for water ==


   AMS_JOBNAME=fixed_coordinates $AMSBIN/ams <<eor

   System
       Atoms
           O         0.001356    0.000999    0.000000
           H         0.994442   -0.037855    0.000000
           H        -0.298554    0.948531    0.000000
       End
   End

   Task GeometryOptimization

   GeometryOptimization
      Convergence Step=1.0e-3
   End

   Constraints
     Coordinate 1 x 0.0
     Coordinate 1 y 0.0
     Coordinate 2 x 1.0
     Coordinate 2 y 0.0
   End

   Engine ADF
       symmetry NoSym
       Basis
        Type DZP
       End
       LinearScaling
           Overlap_Int 98
       End
   EndEngine
   eor

   echo "Angle after optimization:"
   $AMSBIN/amsreport fixed_coordinates.results/adf.rkf -r angle#3#1#2


   # == Example for bond length constraint for water ==


   AMS_JOBNAME=bond_length $AMSBIN/ams <<eor
   System
       Atoms
           O         0.001356    0.000999    0.000000
           H         0.994442   -0.037855    0.000000
           H        -0.298554    0.948531    0.000000
       End
   End

   Task GeometryOptimization

   GeometryOptimization
      Convergence Step=1.0e-3
   End

   Constraints
     Distance  1 2 1.03
     Distance  1 3 1.03
   End

   Engine ADF
       Symmetry NoSym
       Basis
        Type DZP
       End
   EndEngine
   eor

   echo "Bonds distance after optimization:"
   $AMSBIN/amsreport bond_length.results/adf.rkf -r distance#1#2
   $AMSBIN/amsreport bond_length.results/adf.rkf -r distance#1#3


   # == Example for dihedral angle constraint for ethane ==


   AMS_JOBNAME=dihedral $AMSBIN/ams <<eor

   Task GeometryOptimization

   GeometryOptimization
      Convergence Step=1.0e-3
   End

   System
       Atoms
         C        -0.004115   -0.000021    0.000023
         C         1.535711    0.000022    0.000008
         H        -0.399693    1.027812   -0.000082
         H        -0.399745   -0.513934    0.890139
         H        -0.399612   -0.513952   -0.890156
         H         1.931188    0.514066    0.890140
         H         1.931432    0.513819   -0.890121
         H         1.931281   -1.027824    0.000244
       End
   End

   Constraints
     Dihedral 6 2 1 3  20.00
   End

   Engine ADF
       Symmetry NoSym
       Basis
         type DZP
       End
   EndEngine
   eor

   echo "Dihedral after optimization:"
   $AMSBIN/amsreport dihedral.results/adf.rkf -r dihedral#6#2#1#3


   # == Example for Block constraint (with a dihedral constraint) for ethane ==


   AMS_JOBNAME=block_and_dihedral $AMSBIN/ams <<eor
   System
       Atoms
           C   -0.004115   -0.000021    0.000023 region=b1
           C    1.535711    0.000022    0.000008 region=b2
           H   -0.399693    1.027812   -0.000082 region=b1
           H   -0.399745   -0.513934    0.890139 region=b1
           H   -0.399612   -0.513952   -0.890156 region=b1
           H    1.931188    0.514066    0.890140 region=b2
           H    1.931432    0.513819   -0.890121 region=b2
           H    1.931281   -1.027824    0.000244 region=b2
       End
   End

   Task GeometryOptimization

   GeometryOptimization
     Convergence Gradients=1.0e-4 Step=1.0e-3
   End

   Constraints
     Dihedral  6 2 1 3  20.00
     Block b1
     Block b2
   End

   Engine ADF
       Symmetry NoSym
       Basis
         type DZP
       End
   EndEngine
   eor


   echo "Dihedral after optimization:"
   $AMSBIN/amsreport block_and_dihedral.results/adf.rkf -r dihedral#6#2#1#3
   echo "Bonds distance after optimization:"
   $AMSBIN/amsreport block_and_dihedral.results/adf.rkf -r distance#1#3
   $AMSBIN/amsreport block_and_dihedral.results/adf.rkf -r distance#2#6
