The structure is:
qsim/ method/ - exact, pms, rk4 state_vectors.py - creating state vectors and changing between representations hamiltonians.py - create hamiltonian in appropriate format where relevant unitaries.py - create unitary in appropriate format where revant methods.py - evolving a state under a hamiltonian and doing measurements other_helpers - generally hcak and need refactoring helpers.py plotting.py monte_carlo.py - needs refactoring into methods