Figure 7
From: Incorporation of Mg2+ in surface Ca2+ sites of aragonite: an ab initio study
![Figure 7](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs40645-015-0039-4/MediaObjects/40645_2015_39_Fig7_HTML.gif)
Detailed arrangement of CO 3 groups around Mg on the {110} surface. The arrangement of CO3 groups around Mg at the Ca site of the fourth layer in the {110} surface is shown, which suggests that Mg achieves six-coordinate geometry but does not form MgO6 octahedra as in the calcite structure.