anchor.diff:          use qmc_data, only: qmc_in_t, restart_in_t, reference_t, load_bal_in_t, annihilation_flags_t, qmc_state_t
           use dmqmc_data, only: dmqmc_in_t, dmqmc_estimates_t, dmqmc_weighted_sampling_t
   
  -        type(sys_t), intent(inout) :: sys
  +        type(sys_t), intent(in) :: sys
           type(qmc_in_t), intent(inout) :: qmc_in
           type(dmqmc_in_t), intent(inout) :: dmqmc_in
           type(dmqmc_estimates_t), intent(inout) :: dmqmc_estimates
  
positive.code: 
              ! Distribute psips uniformly along the diagonal of the density
              ! matrix.
              call create_initial_density_matrix(rng, sys, qmc_in, dmqmc_in, qs%ref, annihilation_flags, &
                                                 init_tot_nparticles, qs%psip_list, qs%spawn_store%spawn)
  
              ! Allow the shift to vary from the very start of the beta loop, if
  
negative.code:         write_restart_shift = restart_in%write_restart_shift
          call init_restart_info_t(ri, write_id=restart_in%write_id)
  
          ! If averaging over spin spin polarisation will change in general. Copy
          ! system to prevent modification to original system type.
          sys_copy = sys
  
          outer_loop: do beta_cycle = 1, dmqmc_in%beta_loops
  