anchor.diff:  
        end do md_loop
   
  +     current_time = (i+1-equilibration_loops)*tau
  +
        call solvent_cells%random_shift(state(1))
        call apply_pbc(solvent, solvent_cells% edges)
        call apply_pbc(colloids, solvent_cells% edges)
  
positive.code: 
    call n_solvent_el%create_time(hfile%observables, 'n_solvent', &
         n_solvent, ior(H5MD_LINEAR, H5MD_STORE_TIME), step=N_MD_steps, &
         time=N_MD_steps*dt)
  
    call n_plus_el%create_time(hfile%observables, 'n_plus', &
         n_plus, ior(H5MD_LINEAR, H5MD_STORE_TIME), step=N_MD_steps, &
         time=N_MD_steps*dt)
  
    call n_minus_el%create_time(hfile%observables, 'n_minus', &
         n_minus, ior(H5MD_LINEAR, H5MD_STORE_TIME), step=N_MD_steps, &
         time=N_MD_steps*dt)
  
    call link_angle_el%create_time(hfile%observables, 'link_angle', &
         link_angle, ior(H5MD_LINEAR, H5MD_STORE_TIME), step=N_MD_steps, &
         time=N_MD_steps*dt)
  
    call h5gcreate_f(enzyme_io%group, 'box', box_group, error)
    call h5md_write_attribute(box_group, 'dimension', 3)
    call dummy_element%create_fixed(box_group, 'edges', solvent_cells%edges)
    call h5gclose_f(box_group, error)
  
    call solvent% random_placement(solvent_cells% edges, colloids, solvent_colloid_lj, state(1))
  
    call solvent% sort(solvent_cells)
  
negative.code:   call colloids% init(N_colloids, N_species_colloids, mass, system_name='colloids')
    deallocate(mass)
  
    call thermo_data%init(hfile, n_buffer=50, step=N_MD_steps, time=N_MD_steps*dt, &
         step_offset=N_MD_steps, time_offset=N_MD_steps*dt)
  
    call h5gclose_f(params_group, error)
    call PTkill(config)
  
    allocate(kinetics_data(N_enzymes))
    do enzyme_i = 1, N_enzymes
       call kinetics_data(enzyme_i)%bind_substrate%init(block_size=32)
       call kinetics_data(enzyme_i)%release_substrate%init(block_size=32)
       call kinetics_data(enzyme_i)%bind_product%init(block_size=32)
       call kinetics_data(enzyme_i)%release_product%init(block_size=32)
    end do
  
    do enzyme_i = 1, N_enzymes
       colloids% species(3*(enzyme_i-1)+1) = 2
  