update fermionic_operator
Added notation docstring
@@ -391,7 +391,8 @@ class FermionicOperator(object):
@staticmethod
def _two_body_mapping(h2_ijkm, a_i, a_j, a_k, a_m, threshold):
"""
- Subroutine for two body mapping.
+ Subroutine for two body mapping. We use the chemists notation
+ for the two-body term, h2(i,j,k,m) adag_i adag_k a_m a_j.
Args:
h1_ijkm (complex): value of h2 at index (i,j,k,m)
