Figure 1
From: Incorporation of Mg2+ in surface Ca2+ sites of aragonite: an ab initio study
Relaxed atomic arrangement of (a) {001} and (b) {110} surfaces. Red, brown, and blue circles represent O, C, and Ca, respectively. Ca layers are numbered from the top to deeper layers - see text regarding [A] and [B] for the top Ca layer on the {001} surface. In addition, there are two types of sites in the second and third layers of the {001} surface, which are labeled [A′], [B′] and [A″], [B″], respectively.