anchor.diff:          end do
        end do
     end do
  -  
  +
     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)
  
positive.code: 
      colloids%vel(:,enz_2) = com_v
  
      ! todo: deposit extra energy
  
      p = solvent_cells%cartesian_indices(solvent%pos(:, idx))
  
      cell_idx = compact_p_to_h(p, solvent_cells%M) + 1
  
negative.code: 
  
    !> Bind solvent molecule idx to enzyme
    subroutine bind_molecule(enzyme_idx, idx)
      integer, intent(in) :: enzyme_idx
      integer, intent(in) :: idx
  