anchor.diff:          !   sys: system being studied.
           !   qmc_in: input options relating to QMC methods.
           !   quadrature_initiator: how to apply initiator approximation in complex systems.
  +        !   logging_info: information on level of logging to use within calculation.
           ! In/Out:
           !   qs: qmc_state_t containing information about the reference det and estimators.
           !   spawn: spawn_t object containing walkers spawned onto this processor during previous time step.
  
positive.code: 
          type(excit_t) :: connection
          type(hmatel_t) :: hmatel
          integer :: idet, iparticle, nattempts_current_det, ispace
          integer(int_p) :: nspawned, nspawned_im, scratch
          integer(int_p) :: int_pop(spawn_recv%ntypes)
          real(p) :: real_pop(spawn_recv%ntypes)
          real(dp) :: list_pop
  
          type(logging_t) :: logging_info
  
          allocate(cdet%f(sys%basis%tensor_label_len))
          allocate(cdet%data(1))
  
negative.code:         type(dSFMT_t), intent(inout) :: rng
          type(bloom_stats_t), intent(inout) :: bloom_stats
          type(spawn_t), intent(inout) :: spawn
          integer(int_p) :: nspawned, nspawned_im
          type(semi_stoch_t), intent(in) :: determ
  
          type(excit_t) :: connection
  