anchor.diff:    write(*,*) '    i           |    e co so     |   e co co     |   kin co      |   kin so      |   total       |   temp        |'
     write(*,*) ''
   
  +  kin_co = (mass(1)*sum(colloids% vel(:,1)**2)+mass(2)*sum(colloids% vel(:,2)**2))/2
  +  call thermo_write
   
     do i = 1, N_loop
        md: do j = 1, N_MD_steps
  
positive.code:      call simple_mpcd_step(solvent, solvent_cells, mt)
  
       kin_co = (mass(1)*sum(colloids% vel(:,1)**2)+mass(2)*sum(colloids% vel(:,2)**2))/2
       write(*,'(1i16,6f16.3,1e16.8)') i, e1, e2, &
            kin_co, sum(solvent% vel**2)/2, &
            e1+e2+kin_co+sum(solvent% vel**2)/2, &
            compute_temperature(solvent, solvent_cells), &
            sqrt(dot_product(colloids% pos(:,1) - colloids% pos(:,2),colloids% pos(:,1) - colloids% pos(:,2))) - d
  
    end do
  
  
negative.code:   colloids% vel = 0
    
    call random_number(solvent% vel(:, :))
    solvent% vel = (solvent% vel - 0.5d0)*sqrt(12*T)
    solvent% vel = solvent% vel - spread(sum(solvent% vel, dim=2)/solvent% Nmax, 2, solvent% Nmax)
    solvent% force = 0
    solvent% species = 1
  