anchor.diff:    call solvent_io%image%append(solvent%image)
     call solvent_io%species%append(solvent%species)
   
  +  call rho_xy_el%close()
     call dimer_io%close()
     call hfile%close()
     call h5close_f(error)
  
positive.code:         end if 
       end do
    end subroutine buffer_particles
  end program setup_single_dimer
  
negative.code: 
    epsilon = 1.d0
    sigma(1,:) = [sigma_C, sigma_N]
    sigma_cut = sigma*3**(1.d0/6.d0)
    shift = max(sigma_C, sigma_N)*2**(1./6.) + 0.25
    call walls_colloid_lj% init(epsilon(1:1,:), sigma(1:1,:), sigma_cut(1:1,:), shift)
    write(*,*) epsilon(1:2,:), sigma(1:2,:), sigma_cut(1:2,:), shift
  
    mass(1) = rho * sigma_C**3 * 4 * 3.14159265/3
    mass(2) = rho * sigma_N**3 * 4 * 3.14159265/3
  