code: def get_CC_operators():
      """
      Returns a tuple (T1,T2) of unique operators.
      """
      i = symbols("i", below_fermi=True, cls=Dummy)
      a = symbols("a", above_fermi=True, cls=Dummy)
      t_ai = AntiSymmetricTensor("t", (a,), (i,))
      ai = NO(Fd(a) * F(i))
      i, j = symbols("i,j", below_fermi=True, cls=Dummy)
      a, b = symbols("a,b", above_fermi=True, cls=Dummy)
      t_abij = AntiSymmetricTensor("t", (a, b), (i, j))
      abji = NO(Fd(a) * Fd(b) * F(j) * F(i))
  
      T1 = t_ai * ai
      T2 = Rational(1, 4) * t_abij * abji
      return (T1, T2)
  
imports: from sympy.physics.secondquant import AntiSymmetricTensor, wicks, F, Fd, NO, evaluate_deltas, substitute_dummies, Commutator, simplify_index_permutations, PermutationOperator
  from sympy import symbols, Rational, latex, Dummy
label_desc: Use image node_id 1 for calling a global function with example usage: get_CC_operators() and returns: T1,  T2