anchor.diff:  
           if (do_quaternion) call omega_cf%add(i-equilibration_loops, correlate_block_dot, xvec=rigid_janus%omega_body)
   
  -     end if
  +        call janus_io%position%append(colloids%pos)
  +        call janus_io%velocity%append(colloids%vel)
  +        call janus_io%image%append(colloids%image)
  +    end if
   
     end do
     call main%tac()
  
positive.code:   janus_io%id_info%store = .false.
    janus_io%position_info%store = .true.
    janus_io%position_info%mode = ior(H5MD_LINEAR,H5MD_STORE_TIME)
    janus_io%position_info%step = colloid_sampling
    janus_io%position_info%time = colloid_sampling*dt
    janus_io%image_info%store = .true.
    janus_io%image_info%mode = ior(H5MD_LINEAR,H5MD_STORE_TIME)
    janus_io%image_info%step = colloid_sampling
    janus_io%image_info%time = colloid_sampling*dt
    janus_io%velocity_info%store = .true.
    janus_io%velocity_info%mode = ior(H5MD_LINEAR,H5MD_STORE_TIME)
    janus_io%velocity_info%step = colloid_sampling
    janus_io%velocity_info%time = colloid_sampling*dt
    janus_io%species_info%store = .true.
    janus_io%species_info%mode = H5MD_FIXED
    call janus_io%init(hfile, 'janus', colloids)
  
negative.code:            end if
             unit_r = get_unit_r()
             call axial_cf%add_fast((i-equilibration_loops)*N_MD_steps+j-1, v_com, unit_r)
          end if
  
          if ((sampling) .and. (modulo(j, colloid_sampling)==0)) then
             call u_el%append(unit_r)
             call janus_pos_el%append(rigid_janus%pos)
             call janus_vel_el%append(rigid_janus%vel)
             if (do_quaternion) then
                call q_el%append(rigid_janus%q)
                call omega_body_el%append(rigid_janus%omega_body)
  