anchor.diff:    ! init Janus particle
     colloids%species = 1
     colloids%species(1:n_colloids/2) = 1
  -  colloids%species(n_colloids/2+1:n_colloids) = 1
  +  colloids%species(n_colloids/2+1:n_colloids) = 2
     colloids%vel = 0
     colloids%force = 0
     colloids%pos = reshape([13.3745, 8.98251, 4.69069, 8.5896, 7.72357, 4.80796, 9.47026, &
  
positive.code:   call h5md_write_attribute(radial_hist_el%id, 'dx', radial_hist%dx)
    call h5gclose_f(fields_group, error)
  
    call solvent% random_placement(solvent_cells% edges, colloids, solvent_colloid_lj)
  
    call solvent% sort(solvent_cells)
  
negative.code:   call main%init('main')
    call varia%init('varia')
    call time_flag%init('flag')
    call time_refuel%init('refuel')
    call time_change%init('change')
  
    call h5open_f(error)
  