fqe.util.zero_transform

Given a bitstring, determine if it satisfies the occupation and

nonoccupation conditions necessary to be non zero when a product of creation and annihilation operators are applied.

string0 (bitstring) - the occupation representation being acted upon unocc (bitstring) - orbitals which should be unoccupied in string0 occ (bitstring) - orbitals which should be occupied in string0 norb (int) - the number of spatial orbitals for masking the bitstrings

(bool) - true if the transformation is non zero, false if the transformation is zero