Fig. 2
From: Density functional theory modeling of chromate adsorption onto ferrihydrite nanoparticles
The four inner-sphere configurations (a = Mono(A), b = Mono(B), c = Bi(A) and d = Bi(B)) were constructed to test the thermodynamic favorability of surface site types. H = white, O = red, Fe = violet-gray, Cr = magenta