Fig. 4. Differential charge density map for adsorption of O (upper panels) and N2O (lower panels) at the bridge O vacancy on MO2(110). (a and e) M = Ti; (b and f) M = Cr; (c and g) M = Fe; (d and h) M = Ni. Grey, purple, orange, green, red and light purple spheres represent Ti, Cr, Fe, Ni, O and N, respectively. Blue and yellow-red isosurfaces indicate charge depletion and accumulation, respectively. The 2D profile is a cut along two bridge O–M bonds.
