Figure 1.

Crystal surfaces display a variety of atomic surface features. (A) The surface of an ideal crystal may be represented as a periodic two-dimensional arrangement of atoms; these atoms may be coplanar or they may occur at slightly different heights. Real crystals feature surfaces that are typically stepped (B) or kinked (C). Kink sites provide chiral (left- or right-handed) centers (X). Experimental and theoretical studies reveal that molecular adsorption is enhanced at such surface irregularities.