Example: Multiresolution
************************

"Download Multiresolution_H2O.run"

   #! /bin/sh

   # This example demonstrates how to use different levels of numerical precision
   # for different regions, with the aim of increasing computational efficiency.

   # Let us assume that we are interested in having an accurate description only
   # for a subregion of a large chemical system (in this simple example, the
   # central water molecule). The system can be divided into sub-regions and
   # different levels of numerical accuracy can be used for each of these sub-
   # regions.

   # In this example we will tweak:
   # - the basis set (Basis)
   # - the numerical integration (BeckeGrid)
   # - the density fitting for Coulomb potential (ZlmFit)
   # - the fit-set used in the Hartree-Fock Resolution of identity (RIHartreeFock)

   # Note: For the regions for which no quality has been explicitly defined
   # through a QualityPerRegion keyword, the quality defined in NumericalQuality
   # will be used (Normal, in this example).


   $AMSBIN/ams <<eor
   Task SinglePoint

   System
     Atoms
        O    0.00000000    0.00000000    0.00000000   region=Accurate
        H    0.40399229   -0.65578342    0.63241539   region=Accurate
        H    0.81410032    0.55624569   -0.23129097   region=Accurate
        O   -3.02535626   -0.08473104   -0.47678489
        H   -2.56531481    0.62644005    0.07759386
        H   -2.25289644   -0.61700366   -0.80790649
        O    2.95394790   -0.54939973   -0.38206034
        H    3.91427727   -0.21304908   -0.44738291
        H    2.87780992   -1.13241278   -1.20853726
        O   -5.95425742   -0.56764616   -0.02016682   region=Far
        H   -5.26308282   -0.46969096    0.69255963   region=Far
        H   -5.42117992   -0.54361203   -0.86443121   region=Far
        O    6.25171470   -0.62004899   -0.03702467   region=Far
        H    6.16508647   -1.38696453    0.58541903   region=Far
        H    7.09161199   -0.16700550    0.23679419   region=Far
     End
   End

   Engine ADF

      XC
         LibXC B3LYP
      End

      ! ========================================================
      ! Set different basis sets for atoms in different regions:
      ! ========================================================

      Basis
         Type DZ
         Core None
         PerRegion Region=Accurate Type=TZP
         PerRegion Region=Far      Type=SZ
      End

      ! =============================================================
      ! Set the NumerialQuality to be used for the atoms that are not
      ! explicitly defined through a QualityPerRegion keyword
      ! =============================================================

      NumericalQuality Normal

      # ======================
      # Numerical integration:
      # ======================

      BeckeGrid
         QualityPerRegion Region=Accurate Quality=Good
         QualityPerRegion Region=Far      Quality=Basic
      End

     # ======================================
     # Density fitting for Coulomb potential:
     # ======================================

      ZlmFit
         QualityPerRegion Region=Accurate Quality=Good
         QualityPerRegion Region=Far      Quality=Basic
      End

     # ============================================================
     # Hartree-Fock Resolution of identity (for hybrid functionals)
     # ============================================================

      RIHartreeFock
         QualityPerRegion Region=Accurate Quality=Good
         QualityPerRegion Region=Far      Quality=Basic
      End

   EndEngine

   eor
