Example: QMMM with various forcefields
**************************************

"Download qmmm_water.run"

   #!/bin/sh

   # This example shows you how you can use the forcield engine in a qmmm setup
   # Both the regions and the atom typing and charges (if any) go via te AMS system block

   # UFF
   # ===

   AMS_JOBNAME=uff $AMSBIN/ams <<eor

   Task GeometryOptimization

   System
       Atoms
           O -1.8782  0.0294 -0.7574  region=QM 
           H -0.9986  0.2961 -0.3861  region=QM 
           H -1.8623 -0.9560 -0.6510  region=QM 
           O  0.0121 -1.3731  0.5074  region=MM 
           H  0.8930 -1.7879  0.3172  region=MM 
           H -0.5625 -2.1395  0.7656  region=MM 
       End
   End

   Engine Hybrid
       QMMM qmRegion=QM qmEngineID=DFTB mmEngineID=ForceField
       
       Engine DFTB
           Model GFN1-xTB
       EndEngine

       Engine ForceField
           Type UFF
       EndEngine
   EndEngine
   eor


   # Amber
   # =====

   AMS_JOBNAME=amber $AMSBIN/ams <<eor

   Task GeometryOptimization

   System
       Atoms
           O -1.8782  0.0294 -0.7574  region=QM  ForceField.Charge=-0.8340  ForceField.Type=OW
           H -0.9986  0.2961 -0.3861  region=QM  ForceField.Charge=0.4170   ForceField.Type=HW
           H -1.8623 -0.9560 -0.6510  region=QM  ForceField.Charge=0.4170   ForceField.Type=HW
           O  0.0121 -1.3731  0.5074  region=MM  ForceField.Charge=-0.8340  ForceField.Type=OW
           H  0.8930 -1.7879  0.3172  region=MM  ForceField.Charge=0.4170   ForceField.Type=HW
           H -0.5625 -2.1395  0.7656  region=MM  ForceField.Charge=0.4170   ForceField.Type=HW
       End
       BondOrders
            1 2 1.0
            1 3 1.0
            4 5 1.0
            4 6 1.0
       End
   End

   Engine Hybrid
       QMMM qmRegion=QM qmEngineID=DFTB mmEngineID=ForceField
       
       Engine DFTB
           Model GFN1-xTB
       EndEngine

       Engine ForceField
           Type Amber95
           ForceFieldFile $AMSHOME/atomicdata/ForceFields/amber95.ff
       EndEngine
   EndEngine
   eor

   # Tripos
   # ======

   AMS_JOBNAME=tripos $AMSBIN/ams <<eor

   Task GeometryOptimization

   System
       Atoms
           O -1.8782  0.0294 -0.7574  region=QM  ForceField.Charge=-0.8340   ForceField.Type=O.3
           H -0.9986  0.2961 -0.3861  region=QM  ForceField.Charge=0.4170    ForceField.Type=H
           H -1.8623 -0.9560 -0.6510  region=QM  ForceField.Charge=0.4170    ForceField.Type=H
           O  0.0121 -1.3731  0.5074  region=MM  ForceField.Charge=-0.8340   ForceField.Type=O.3
           H  0.8930 -1.7879  0.3172  region=MM  ForceField.Charge=0.4170    ForceField.Type=H
           H -0.5625 -2.1395  0.7656  region=MM  ForceField.Charge=0.4170    ForceField.Type=H
       End
       BondOrders
            1 2 1.0
            1 3 1.0
            4 5 1.0
            4 6 1.0
       End
   End

   Engine Hybrid
       QMMM qmRegion=QM qmEngineID=DFTB mmEngineID=ForceField
       
       Engine DFTB
           Model GFN1-xTB
       EndEngine

       Engine ForceField
           Type Tripos5.2
           ForceFieldFile $AMSRESOURCES/ForceFields/tripos5.2.ff
       EndEngine
   EndEngine
   eor
