anchor.diff:         'N/A', 'Pierre de Buyl')
     call thermo_data%init(hfile, n_buffer=50, step=N_loop, time=N_MD_steps*dt)
   
  -  call dimer_io%init(hfile, 'dimer', colloids, H5MD_LINEAR, position_step=N_loop, position_time=N_MD_steps*dt)
  -
     call PTkill(config)
     
     open(15,file ='dimerdata_chemConc.txt')
  
positive.code:         call concentration_field
          write(16,*) conc_z, colloid_pos
       end if
  
       call varia%tic()
       kin_co = (colloids% mass(1)*sum(colloids% vel(:,1)**2)+ colloids% mass(2)*sum(colloids% vel(:,2)**2))/2
  
       write(12,'(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  
       call varia%tac()
  
    end do
    call main%tac()
  
negative.code:   colloids% pos(:,1) = solvent_cells% edges/2.0
    colloids% pos(:,2) = solvent_cells% edges/2.0 
    colloids% pos(1,2) = colloids% pos(1,2) + d
  
    call h5gcreate_f(dimer_io%group, 'box', box_group, error)
    call h5md_write_attribute(box_group, 'dimension', 3)
    call dummy_element%create_fixed(box_group, 'edges', solvent_cells%edges)
    call h5gclose_f(box_group, error)
  
    call solvent% random_placement(solvent_cells% edges, colloids, solvent_colloid_lj)
  
    call solvent% sort(solvent_cells)
  