#!/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.
"$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