anchor.diff:    double precision :: skin, co_max, so_max
     integer :: N_MD_steps, N_loop
     integer :: n_extra_sorting
  -  double precision :: kin_co
  +  double precision :: kin_e, temperature
   
     double precision :: conc_z(400)
     double precision :: colloid_pos(3,2)
  +  type(h5md_file_t) :: hfile
  +  type(thermo_t) :: thermo_data
   
     type(PTo) :: config
     integer(c_int64_t) :: seed
  
positive.code:   !e_wall = colloid_wall_interaction(colloids, walls_colloid_lj,solvent_cells% edges)
    solvent% force_old = solvent% force
    colloids% force_old = colloids% force
    write(*,*) colloids% force
    write(*,*) ''
    write(*,*) '    i           |    e co so     |   e co co     |   kin co      |   kin so      |   total       |   temp        |'
    write(*,*) ''
  
    call vx% init(0.d0, solvent_cells% edges(3), L(3))
  
    i = 0
    kin_co = (mass(1)*sum(colloids% vel(:,1)**2)+mass(2)*sum(colloids% vel(:,2)**2))/2
    call thermo_write
    !start RMPCDMD
    setup: do i = 1, N_loop
       md: do j = 1, N_MD_steps
          call mpcd_stream_zwall_light(solvent, solvent_cells, dt,g)
  
  
negative.code:            do k=1, colloids% Nmax 
                if (colloids% pos(1,k) > bufferlength) then
                   on_track = .false.
                   write(*,*) 'on_track', on_track
                end if 
             end do
          end if
  