anchor.diff:    integer :: n_extra_sorting
     double precision :: kin_co
   
  +  double precision :: conc_z(400)
  +  double precision :: colloid_pos(3,2)
  +
     type(mt19937ar_t), target :: mt
     type(PTo) :: config
   
  
positive.code:     double precision :: x(3)
      integer :: n
  
      far = (L(1)/2)**2
  
  
      do n = 1,solvent% Nmax
  
negative.code:   colloids% pos(:,2) = solvent_cells% edges/2.0 
    colloids% pos(1,2) = colloids% pos(1,2) + d
    
    write(*, *) colloids% pos  
  
    call solvent% random_placement(solvent_cells% edges, colloids, solvent_colloid_lj)
  
    call solvent% sort(solvent_cells)
  