Example: ROKS: SF
*****************

"Download SF_ROKS.run"

   #!/bin/sh

   # Example restricted open shell Kohn-Sham (ROKS, ROSCF) for SF.

   # The method implemented in ADF needs integer occupation numbers,
   # and a positive spin polarization.
   # In this case one can not use full C(lin) symmetry, since one of
   # the orbitals in one of the degenerate representation might not
   # be fully occupied or zero.
   # If one would use C(lin) one of the orbitals in the degenerate 
   # irrep Pi would have 1 beta electron.
   # This looks like an integer number, however, 1 beta electron in Pi
   # effectively would lead to a fractional 0.5 electron in Pi:x and
   # 0.5 electron in Pi:y beta orbital.
   # Since this method needs integer occupations, a lower symmetry is
   # used, in this case C(2v).
   # Note that in this case one needs to use the key Occupations IntegerAufbau
   # or explicit integer occupation numbers with the key IrrepOccupations, 
   # otherwise one could still end up with fractional occupation numbers.

   # Note that the ROSCF method is less useful for electron
   # configurations with 1 electron in a multidemensional irrep,
   # since it will loose orbital degeneracy.

   "$AMSBIN/ams" << eor
   Task SinglePoint
   System
       Atoms
           S  0.0000 0.0000 0.0000
           F  0.0000 0.0000 1.6000
       End
   End

   Engine ADF
       Basis
           Type TZ2P
           Core None
       End
       SpinPolarization 1
       XC
           Hybrid B3LYP
       End
       Scf
           ROSCF
           End
       End
       symmetry C(2v)
       Unrestricted Yes
       Occupations IntegerAufbau
       NumericalQuality Good
       IrrepOccupations
          A1 7 // 7
          B1 3 // 3
          B2 3 // 2
       End
   EndEngine
   eor
