Dependence of magnetic moment of transitional metal atom on support. (a) Magnetic moment of 3d transition-metal atoms supported on metal substrates (144, 145). [Image in a reprinted in part from ref. 144 (Copyright 1996, American Physical Society) and in part from ref. 145 (Copyright 1994, Elsevier).] (b) Magnetic moments of neutral transition-metal atoms, free and supported on benzene (135, 137). [Image in b reprinted with permission from ref. 135 (Copyright 2000, Elsevier).]