#! /bin/sh

# GW calculation for Water. By default. The highest 5 occupied and lowest 5
# unoccupied states are calculated.

# We use an all-electron basis set since core-correlation effects are important. 
# A QZ basis set is recommended for relatively converged QP energies 

# Fot this example we will use the GGA PBE.
# This is NOT a recommended starting point for a G0W0 calculation. 
# However, the eigenvalue-only self-consistency removes most of the #
# starting point dependence of the functional. 
# Thererfore, PBE is a reasonable choice.  

# RECOMMENDED: VeryGood numerical quality, 
# especially in self-consistent GW calculations. 

$AMSBIN/ams << eor
Symmetry
  SymmetrizeTolerance 0.001
End

System
  Atoms
    O    2.220871067   0.026716792   0.000620476
    H    2.597492682  -0.411663274   0.766744858
    H    2.593135384  -0.449496183  -0.744782026
  End
  Symmetrize Yes
End

task SinglePoint

Engine band
  Basis
    Core None
    Type Corr/QZ6P
  end

  NumericalQuality VeryGood

  Dependency
     AllowBasisDependency True
     basis 1e-4
  End

  RIHartreeFock
     DependencyThreshold 1e-3
  End

  SoftConfinement
     Quality Excellent
  End

  usesymmetry False

  XC
    gga PBE
  end

  GW
     selfconsistency evGW
  END
EndEngine
eor