pydmqmc.utils.get_single_perm
- pydmqmc.utils.get_single_perm(b1, a, r, nel)
Return new bitarray and the number of permutations for a single excitation.
- Parameters:
- b1array
The bitarray of the initial state.
- aint
The index of the occupied orbital to be vacated.
- rint
The index of the unoccupied orbital to be filled.
- nelint
The number of electrons in the system.
- Returns:
- array
The new bitarray after the excitation.
- int
The number of permutations associated with the excitation.